ThZeal - The Zeal

Description of Policy

Board Composition

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Reasonable Size. Our Board shall be between five and 10 directors.

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No Overboarded Directors. Our directors sit on three or fewer boards of other public companies.

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Mandatory Retirement. Our Board has fixed the retirement age for directors at 75.

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Tenure Limit. Our Board has set the maximum tenure for non-employee directors at 12 years, except that the maximum tenure is 15 years for directors whose service began prior to 2014.

Director Independence

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Majority Independent. A majority of our directors satisfy Nasdaq independence standards.

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Regular Executive Sessions. Our independent directors meet in executive session following each regular meeting of the Board, each meeting of the Audit Committee, and certain other committee meetings.

Board Leadership Structure

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Robust Presiding Director Role. Since our CEO is also Chairman, our independent directors select one of themselves to serve on a rotating basis as Presiding Director, with established roles and responsibilities. See the Board Leadership Structure section following this table on page 20 for further details.

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Annual Review. The Board annually appoints a Chair and determines whether the positions of Chair and CEO will be held by one individual or separated.

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No. )

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

☐

Preliminary Proxy Statement

☐

Confidential, for Use of the Commission Only (as permitted by Rule 14a 6(e)(2))

☒

Definitive Proxy Statement

☐

Definitive Additional Materials

☐

Soliciting Material under §240.14a 12

Tetra Tech, Inc.

(Name of Registrant as Specified in Its Charter)

N/A

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

☒

No fee required.

☐

Fee paid previously with preliminary materials.

☐

Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a 6(i)(1) and 0-11.

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Today, Tetra Tech’s high-end consulting and engineering services are more in demand than ever before. With our focus on Leading with Science®, we are ideally positioned to provide the sustainable solutions that are needed in a changing world.

Dan Batrack
Chairman and Chief Executive Officer

January 2025

Dear Tetra Tech Stockholders:

You are cordially invited to attend the 2025 Annual Meeting of Stockholders of Tetra Tech, which will be held on Thursday, February 27, 2025, at 10:00 a.m. Pacific Time.

Details of the business to be conducted at the 2025 Annual Meeting are given in the accompanying Notice of 2025 Annual Meeting of Stockholders and the proxy statement.

We use the internet as our primary means of furnishing proxy materials to our stockholders. We will mail a Notice of Internet Availability of Proxy Materials to our stockholders of record that did not request to receive a printed copy of our proxy materials on or about January 16, 2025 with instructions for accessing the proxy materials and voting via the Internet. Consequently, most stockholders will not receive paper copies of our proxy materials and will instead receive a notice with instructions for accessing the proxy materials and voting via the internet. The notice also provides information on how stockholders can obtain paper copies of our proxy materials if they so choose. Internet transmission and voting are designed to be efficient, minimize cost, and conserve natural resources.

Whether or not you plan to attend the 2025 Annual Meeting, please vote as soon as possible. As an alternative to voting in person at the 2025 Annual Meeting, you may vote via the internet, by telephone, or by mail. Voting by any of these methods will ensure your representation at the 2025 Annual Meeting.

Thank you for your continued support of Tetra Tech. We look forward to seeing you at the 2025 Annual Meeting.

Sincerely,

Dan Batrack
Chairman and Chief Executive Officer

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3475 E. Foothill Boulevard, Pasadena, California 91107
(626) 351-4664
www.tetratech.com

Notice of 2025 Annual
Meeting of Stockholders

2025 Annual Meeting of Stockholders

	Date			Thursday, February 27, 2025
	Time			10:00 a.m. Pacific Time
	Place			Le Méridien Pasadena Arcadia 130 West Huntington Drive Arcadia, California 91007
	Record Date			January 2, 2025

Items of Business

Proposal		Board Recommendation
Item 1	To elect the seven directors nominated by our Board to serve a one-year term until the 2026 Annual Meeting of Stockholders (2026 Annual Meeting), and until their respective successors are duly elected and qualified or until his or her resignation or removal	FOR
Item 2	To approve, on an advisory basis, our named executive officers’ compensation	FOR
Item 3	To ratify the appointment of PricewaterhouseCoopers LLP as our independent registered public accounting firm for fiscal year 2025	FOR
To transact such other matters that may properly come before the 2025 Annual Meeting or any postponement or adjournment thereof

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How to vote: Your vote is important


Internet	Telephone	Mail	In Person
Follow the instructions provided in the Notice, separate proxy card, or voting instruction form you received.	Follow the instructions provided in the separate proxy card or voting instruction form you received.	Send your completed and signed proxy card or voting instruction form to the address on your proxy card or voting instruction form.	You can vote in person at the 2025 Annual Meeting. Beneficial holders must contact their broker or other nominee if they wish to vote in person.

Dear Tetra Tech Stockholders:

Your vote is important. Even if you cannot attend the 2025 Annual Meeting, it is important that your shares be represented and voted. To ensure your representation at the 2025 Annual Meeting, you may submit your proxy and voting instructions via the internet, by telephone, or by mail by following the instructions listed on your proxy card, notice, or voting instruction form.

Please refer to “Voting Your Shares” in the Meeting and Voting Information section on page 80 of the accompanying proxy statement for a description of each voting method. If your shares are held by a bank, broker, or other nominee (your record holder) and you have not given your record holder instructions on how to vote your shares, your record holder will not be able to vote your shares on any matter other than ratification of the appointment of the independent registered public accounting firm. We strongly encourage you to vote.

On behalf of the Board of Directors, management, and employees of Tetra Tech, we thank you for your continued support.

By order of the Board of Directors,

Preston Hopson
Secretary
January 16, 2025
Pasadena, California

Important Notice about the Availability of Proxy Materials. The Notice of the 2025 Annual Meeting, proxy statement, and our 2024 Annual Report on Form 10-K are available at proxyvote.com. You are encouraged to access and review all the important information contained in our proxy materials before voting.

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Contents

	Special Note Regarding Forward-Looking Statements					1
	Proxy Summary					2
	Tetra Tech					2
	Items Being Voted on at the 2025 Annual Meeting					2
	Fiscal Year 2024 Performance Highlights					3
	Corporate Governance Highlights					3
	2025 Director Nominees					4
	Executive Compensation Highlights					6
	Ratification of Appointment of PricewaterhouseCoopers LLP					8
	Corporate Governance, Sustainability, and Social Responsibility					9
	Corporate Governance					9
	Corporate Sustainability					10
	Billion People Challenge Baseline and Goals					10
	Human Capital Metrics and Goals					11
	Operational GHG Results and Goals					12
	Corporate Social Responsibility					13
	Human Capital Management					14
	Health and Safety					14
	Health and Safety Results and Goals					14
	Diversity, Equity, Inclusion & Accessibility					15
	Professional Development					16
	Our Board of Directors					18
	Board Composition					18
	Board Meetings and Attendance					18
	Corporate Governance Policies					18
	Director Independence					19
	Board Leadership Structure					19
	Board Committees					20
	Executive Sessions					23
	Oversight of Risk Management					23
	Succession Planning					24
	Director, Board, and Committee Evaluations					24
	Selection of Director Nominees					25
	Stockholder Submission of Director					25
	Director Qualifications					26
	Board Refreshment					27
	Director Diversity					28
	Active Stockholder Engagement and Communication Policy					28
	Item 1: Election of Directors					29
	Vote Required					29
	Recommendation of Board of Directors					29
	2025 Director Nominees					29
	Director Compensation					33
	Item 2: Advisory Vote to Approve Our Named Executive Officers’ Compensation					36
	Vote Required					36
	Recommendation of Board of Directors					36
	Meaning of Advisory Vote					36
	Compensation Discussion and Analysis					37
	Strong Compensation Governance Practices					39
	2024 Say on Pay Vote and Executive Compensation Program					40
	Pay Philosophy and Executive Compensation Components					41
	Summary of Compensation Decisions for FY 2024					43

	Assessment of Pay for Performance					44
	Discussion of Compensation Components and Decisions Impacting FY 2024 Compensation					44
	Other Benefits					52
	Termination and Change in Control					53
	Compensation Setting Process and Tools					53
	Independent Oversight and Expertise					54
	Advisor Independence					54
	Stock Ownership Guidelines					55
	Clawback Policy					55
	Policies and Practices Related to the Timing of Option and SAR Awards					55
	Insider Trading, Anti Hedging, and Anti Pledging Policy					55
	Tax and Accounting Implications of Executive Compensation					55
	Compensation Committee Report					56
	Compensation Committee Interlocks and Insider Participation					56
	Executive Compensation Tables					57
	Summary Compensation Table					57
	Grants of Plan Based Awards—FY 2024					59
	Outstanding Equity Awards at FYE 2024					60
	Options Exercised and Stock Vested—FY 2024					61
	Nonqualified Deferred Compensation—FY 2024					62
	Potential Payments upon Termination or Change in Control					62
	Equity Compensation Plan Information					67
	Pay Ratio Disclosure					68
	Pay Versus Performance Disclosure					72
	Item 3: Ratification of Appointment of Independent Registered Public Accounting Firm					73
	Vote Required					73
	Recommendation of Board of Directors					73
	Auditor Independence					73
	Auditor Fees					74
	Policy on Audit Committee Pre-Approval of Audit and Permissible Non-Audit Services					74
	Audit Committee Report					75
	Security Ownership Information					76
	Security Ownership of Management and Significant Stockholders					76
	Section 16(a) Beneficial Ownership Reporting Compliance					77
	Related Person Transactions					77
	Meeting and Voting Information					78
	Delivery of Annual Report on Form 10-K					78
	Delivery of Proxy Materials					78
	Householding					78
	Shares Entitled to Vote					78
	Voting Your Shares					79
	Revoking Your Proxy or Changing Your Vote					79
	Quorum and Votes Required					80
	Vote Results					80
	Proxy Solicitation					80
	Electronic Access to Proxy Materials and Annual Report					80
	Annual Meeting Procedures					81
	Submission of Stockholder Items for 2026 Annual Meeting					81
	Other Matters					82

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Special Note Regarding Forward-Looking Statements

This proxy statement contains forward-looking statements regarding future events and our future results that are subject to the safe harbors created under the Securities Act of 1933, as amended (Securities Act) and the Securities Exchange Act of 1934, as amended (Exchange Act). All statements other than statements of historical facts are statements that could be deemed forward-looking statements. These statements are based on current expectations, estimates, forecasts and projections about the industries in which we operate and the beliefs and assumptions of our management. Words such as “expects,” “anticipates,” “targets,” “goals,” “projects,” “intends,” “plans,” “believes,” “estimates,” “seeks,” “continues,” “may,” variations of such words and similar expressions are intended to identify such forward-looking statements. In addition, statements that refer to projections of our future financial performance, our anticipated growth and trends in our businesses and other characterizations of future events or circumstances are forward-looking statements. Readers are cautioned that these forward-looking statements are only predictions and are subject to risks, uncertainties and assumptions that are difficult to predict, including those discussed under “Part I—Item 1A. Risk Factors,” in our Annual Report on Form 10-K for the year ended September 29, 2024 and other U.S. Securities and Exchange Commission (SEC) filings, including future SEC filings. Therefore, actual results may differ materially and adversely from those expressed in any forward-looking statements. In particular, ESG goals included in this proxy statement are aspirational and do not constitute assurances that such goals will be achieved. Historical and forward-looking ESG-related statements may be based on standards that are still developing, internal Company controls and processes that continue to evolve, and assumptions that are subject to change. ESG-related figures and percentages in this report include estimates or approximations and may be based on assumptions or incomplete data.

All forward-looking statements are necessarily only estimates of future results, and there can be no assurance that actual results will not differ materially from our expectations. You are therefore cautioned not to place undue reliance on such statements. Any forward-looking statements are qualified in their entirety by reference to the risk factors discussed throughout the documents incorporated by reference in this proxy statement. Further, any forward-looking statement speaks only as of the date on which it is made, and we undertake no obligation to update any forward-looking statement to reflect events or circumstances after the date on which the statement is made or to reflect the occurrence of unanticipated events.

Tetra Tech 2025 Proxy Statement 1

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Proxy Summary

This section contains summary information explained in greater detail in other parts of this proxy statement and does not contain all the information you should consider before voting. Stockholders are urged to read the entire proxy statement before voting. On January 16, 2025, we intend to make our proxy materials, including this proxy statement, available to all stockholders entitled to vote at the 2025 Annual Meeting.

Tetra Tech

Tetra Tech is a leading global provider of high-end consulting and engineering services that focuses on water, environment and sustainable infrastructure. We are a global company that is Leading with Science® to provide innovative solutions for our public and private clients. We typically begin at the earliest stage of a project by identifying technical solutions and developing execution plans tailored to our clients’ needs and resources.

Engineering News-Record (ENR), the engineering industry’s leading magazine, has ranked Tetra Tech #1 in Water Treatment for 11 years in a row. In 2024, we were also ranked #1 in consulting studies, environmental management, wind power, hydro plants, offshore and underwater facilities, site assessment and compliance, and green government offices. ENR also ranked Tetra Tech in the top 10 in numerous categories, including dams and reservoirs, marine and port facilities, power, solar power, solid waste, environmental science, chemical and soil remediation, and hazardous waste.

Our reputation for high-end consulting and engineering services and our ability to develop innovative, sustainable solutions for water and environmental management have supported our growth for more than 50 years. Today, we are proud to be making a difference in people’s lives worldwide through our high-end consulting, engineering, and technology service offerings. In FY 2024 with a talent force of 30,000 employees, we worked on more than 100,000 projects in over 100 countries on all seven continents. We are Leading with Science® throughout our operations, with domain experts across multiple disciplines supported by our advanced analytics, artificial intelligence, machine learning, and digital technology solutions. Our ability to provide innovation and first-of-a-kind solutions is enhanced by partnerships with our forward-thinking clients. We are diverse, equitable, and inclusive, embracing the breadth of experience across our talented workforce worldwide with a culture of innovation and entrepreneurship. We are disciplined in our business and focused on delivering value to customers and high performance for our stockholders. In supporting our clients, we seek to add value and provide long-term sustainable consulting, engineering, and technology solutions.

Items Being Voted on at the 2025 Annual Meeting

Stockholders will be asked to vote on the following items at the 2025 Annual Meeting:

Item	Board Recommendation	Vote Required	Discretionary Broker Voting
Item 1. Election of directors	FOR each nominee	Majority of votes cast	No
Item 2. Advisory vote to approve named executive officers’ compensation	FOR	Majority of shares represented and entitled to vote on the item	No
Item 3. Ratification of appointment of PricewaterhouseCoopers LLP as independent registered public accounting firm for fiscal year 2025	FOR	Majority of shares represented and entitled to vote on the item	Yes

Tetra Tech 2025 Proxy Statement 2

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Proxy Summary

Fiscal Year 2024 Performance Highlights1

Tetra Tech’s fiscal year (FY) 2024 operating results were strong and demonstrated increased performance compared to FY 2023, which was itself a year of strong operational and financial performance. In FY 2024 we achieved record annual results for revenue, operating income, adjusted EBITDA, earnings and cash flow. Our focus on providing clients with high-end differentiated consulting and engineering services has resulted in increased margins and reduced risk in our business.

We ended FY 2024 with an authorized and funded backlog that reached another all-time high of approximately $5.4 billion.

Highlights of our FY 2024 results of operations as reported in our FY 2024 Annual Report on Form 10-K are noted in the table below.

FY 2024 Highlights
($ in millions, except EPS and percentages)

	$	vs. FY 2023
Revenue	$5,199	+15%
Operating Income	$501	+40%
EPS	$1.23	+21%
Backlog	$5,376	+12%

Strong Stock Price Performance

Our total stockholder return (TSR) for the last year was 53% and our cumulative three-year TSR was 55%. TSR measures the return we have provided our stockholders, including stock price appreciation and dividends paid (assuming reinvestment thereof). We compare our TSR to the S&P 1000 and our TSR peer group (listed on page 53 of this proxy statement) for purposes of our long-term incentive (LTI) program, as more fully explained below. We outperformed these market comparisons over both the one-year period and three-year period.

Disciplined Capital Allocation

Deploying capital effectively is one of our core strategies. We have been consistently disciplined in our execution of that strategy by returning cash to our stockholders through dividends and stock repurchases, while being a strategic and financially disciplined business with respect to investing in our organic growth and strategic acquisitions. Over the last three years, we have returned $357 million to stockholders through dividends and stock repurchases.

Corporate Governance Highlights

Our corporate governance policies and practices reflect our principles (discussed in the Corporate Governance, Sustainability, and Social Responsibility section on page 9 of this proxy statement) and allow our Board to effectively oversee our Company in the interest of creating long-term value. The key elements of our program and the related benefits to our stockholders are set forth in the following table.

1 On September 9, 2024, we completed a five-for-one forward stock split of our common stock. All share, equity award and per share amounts presented in this proxy statement have been retroactively adjusted, where applicable, to reflect the stock split.

Tetra Tech 2025 Proxy Statement 3

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Proxy Summary

Corporate Governance Key Elements

	Stockholder Rights				Board Structure				Executive Compensation
	• Annual Election of Directors • Single Class of Voting Stock • Majority Voting for Director Elections • Mandatory Director Resignation Policy • No Poison Pill • Stockholder Calls for Special Meetings • Stockholder Action by Written Consent • Majority Voting for Charter Amendments • Proxy Access				• ~90% Independent Directors • Director Diversity with over 40% Female Representation • Robust Presiding Director Role • Term Limits and Mandatory Retirement • Board Refreshment • Annual Evaluations • Executive Sessions at Board and Committee Meetings • Access to Management and Experts • Succession Planning for CEO and Leadership				• At-Risk, Performance-Based Compensation • Environmental, Social, and Governance (ESG) Factors • Annual Say-On-Pay Vote • Executive and Director Stock Ownership Guidelines • Compensation Committee of All Independent Directors • Independent Compensation Consultant to the Committee • Best Practices

2025 Director Nominees

Our Board has overseen the continuing transformation of our Company, including our strategic decision to focus on our high-end consulting and engineering business. Further, the Board has overseen the continuation of our capital allocation plan, which included cash dividends of $59 million in FY 2024. Our Board members have demonstrated their commitment to diligently and effectively executing their fiduciary duties on behalf of our stockholders, and we recommend that each of our incumbent directors (introduced in the table below) be reelected at the 2025 Annual Meeting.

Tetra Tech 2025 Proxy Statement 4

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Proxy Summary

2025 Director Nominees

Name

Age

Director Since

Principal Occupation

Independent

Dan L. Batrack

2005

Chairman and Chief Executive Officer (CEO), Tetra Tech

Gary R. Birkenbeuel

2018

Retired Regional Assurance Managing Partner, Ernst & Young LLP

•

John M. Douglas

2024

Retired Chief Executive Officer, RPS Group Plc

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Prashant Gandhi

2022

Chief Business Officer, Melio Payments

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Christiana Obiaya

2023

Chief Executive Officer, Heliogen

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Kimberly E. Ritrievi

2013

President, The Ritrievi Group LLC

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Kirsten M. Volpi*

2013

EVP, Chief Operating Officer, and Chief Financial Officer, Colorado School of Mines

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Meetings Held

Notes:

AC= Audit Committee

CC= Compensation Committee

NC= Nominating and Corporate Governance Committee

C = Committee Chair

* = Presiding Director

Tetra Tech 2025 Proxy Statement 5

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Proxy Summary

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Executive Compensation Highlights

Our Board’s Compensation Committee designs our executive compensation program to motivate our executives to implement our business strategies and deliver long-term stockholder value. We pay for performance with compensation dependent on our achieving financial, share price, and business performance objectives, while aligning executives with the long-term interests of our stockholders. The following graphic illustrates the annual and long-term components of executive compensation.

Tetra Tech 2025 Proxy Statement 6

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Proxy Summary

FY 2024 Components of Annual and Long-Term Compensation

Compensation Best Practices

As summarized below and described in further detail in the Compensation Discussion and Analysis section on page 39 of this proxy statement, our executive compensation program is aligned with our goals and strategies and reflects what we believe are best practices.

What We Do
	Focus on pay for performance: In FY 2024, 88% of our Chief Executive Officer’s (CEO’s) target total direct compensation (TDC) and an average of 72% of our other named executive officers’ (NEOs’) target TDC was at-risk	Review the Compensation Committee’s charter, and evaluate the Compensation Committee’s performance
	Emphasize long-term performance: In FY 2024, 70% of our CEO’s target TDC and an average of 47% of our other NEOs’ target TDC was equity based and, thereby, tied to creating stockholder value	Use an independent compensation consultant retained directly by the Compensation Committee
	Require double trigger for change in control equity vesting and cash severance benefits	Assess potential risks relating to our compensation policies and practices
	Maintain stock ownership guidelines for both executives and the Board of Directors	Maintain a clawback policy

Tetra Tech 2025 Proxy Statement 7

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Proxy Summary

What We Do Not Do
	Have employment agreements with our NEOs	Grant stock options with an exercise price less than the fair market value on the date of grant
	Provide excise tax gross up payments in connection with change in control severance benefits	Reprice or exchange stock options
	Provide gross ups to cover tax liabilities associated with executive perquisites	Promise multiyear guarantees for bonus payouts or salary increases
	Permit directors, officers, or employees to hedge or pledge Company stock	Pay dividends or dividend equivalents on equity awards unless and until the awards vest

FY 2024 Target Total Direct Compensation Mix1

1 See the Compensation Discussion and Analysis section on page 39 of this proxy statement for a description of how these amounts are determined.

Ratification of Appointment of PricewaterhouseCoopers LLP

Our Board’s Audit Committee has appointed PricewaterhouseCoopers LLP (PwC) as our independent registered public accounting firm for the 2025 fiscal year, and our Board is seeking stockholder ratification of the appointment. PwC is knowledgeable about our operations and accounting practices and is well qualified to act as our independent registered public accounting firm. The Audit Committee considered the qualifications, performance, and independence of PwC; the quality of its discussions with PwC; and the fees charged by PwC for the level and quality of services provided during FY 2024 and has determined that the reappointment of PwC is in the best interest of our Company and our stockholders.

Tetra Tech 2025 Proxy Statement 8

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Corporate Governance, Sustainability, and Social Responsibility

Tetra Tech’s Mission, Purpose, and Core Principles

	Our Mission: To be the premier worldwide high-end consulting and engineering firm, focusing on water, environment, and sustainable infrastructure.
	Core Principles Our core principles form the underpinning of how we work together to serve our clients. • Service: Tetra Tech puts our clients first. We listen to better understand our clients’ needs and deliver smart, cost-effective solutions that meet those needs. • Value: Tetra Tech takes on our clients’ problems as if they were our own. We develop and implement innovative solutions that are cost effective, efficient, and practical. • Excellence: Tetra Tech brings superior technical capability, disciplined project management, and excellence in safety and quality to all our work. • Opportunity: Our people are our number one asset. Our workforce is diverse and includes leading experts in our fields. Our entrepreneurial nature and commitment to success provide challenges and opportunities for all our employees.			Purpose Tetra Tech will enhance the quality of life while creating value for customers, employees, investors, and partners.

Corporate Governance

Under the oversight of our Board of Directors, we have designed our Corporate Governance Program to ensure continued compliance with applicable laws and regulations, the rules of the Securities and Exchange Commission (SEC), and the listing standards of the Nasdaq Stock Market (Nasdaq); and to reflect best practices as informed by the recommendations of our outside advisors, the voting guidelines of our stockholders, the policies of proxy advisory firms, and the policies of other public companies.

We are committed to operating with honesty and integrity and maintaining the highest level of ethical conduct. We encourage stockholders to visit the Corporate Governance section on our website at investor.tetratech.com/esg/governance-overview, which includes the following corporate governance documents:

•

Corporate Code of Business Ethics and Conduct

•

Finance Code of Professional Conduct, which applies to our Chief Executive Officer (CEO) and all members of our finance department, including our Chief Financial Officer (CFO) and Chief Accounting Officer (CAO)

•

Corporate Governance Policies (see page 19 of this proxy statement for more detail on our Corporate Governance policies)

•

Charters for our Board’s Audit Committee, Compensation Committee, and Nominating and Corporate Governance (NCG) Committee

•

Stock Ownership Guidelines

Information on our website is not and should not be considered part of, nor incorporated by reference into, this proxy statement. You can also receive copies of these documents, without charge, by written request mailed to our Corporate Secretary at Tetra Tech, 3475 E. Foothill Boulevard, Pasadena, California 91107.

We maintain a 24-hour hotline that is available to all employees for the anonymous, confidential submission of employee, whistleblower and other complaints or concerns by telephone and internet. The hotline is operated by Navex Global, an independent third-party provider. All complaints go directly to our Chief Legal Officer and Chief Compliance Officer, all complaints relating to accounting, internal controls, or auditing matters also go directly to the Chair of our Audit Committee, and all other complaints go directly to the Nominating and Corporate Governance Committee; our Chief Legal Officer and Chief Compliance Officer provides regular reports on these complaints to the Audit Committee and Nominating and Corporate Governance Committee. We also maintain an

Tetra Tech 2025 Proxy Statement 9

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Corporate Governance, Sustainability, and Social Responsibility

internal audit function that provides critical oversight over the key areas of our business and financial processes and controls and reports directly to the Audit Committee. Our Board has adopted a written “related person transactions” policy. Under the policy, the Audit Committee (or other committee designated by the NCG Committee) reviews transactions between Tetra Tech and “related persons.” Tetra Tech had no related person or related party transactions in FY 2024.

Tetra Tech conducts our business on the basis of the quality of our services and the integrity of our association with our clients and others. Our Corporate Code of Business Ethics and Conduct demonstrates our commitment to upholding the highest standards of ethical conduct in the pursuit of our business and applies to all our directors, officers, and employees. We require all directors, officers, and employees, and where necessary and appropriate, suppliers, contractors, and other business partners acting on our behalf, to complete periodic Code of Business Ethics and Conduct trainings. Our policies have been translated into five languages, and our employees are trained on and affirm their commitment to complying with the policies when they first join our Company and regularly thereafter.

Corporate Sustainability

Tetra Tech supports clients in more than 100 countries around the world, helping them to solve complex problems and achieve solutions that are technically advanced. Our high-end consulting and engineering services focus on using innovative technologies and creative solutions to minimize environmental impacts and enhance social systems. Our greatest contribution toward sustainability is through the projects we perform every day for our clients, including water reuse programs, decarbonization of buildings, ecosystem restoration, and renewable energy transformation. In developing countries, we also support social programs such as gender equality programs, and enhancement of sustainable aquaculture and forestry economies. As a signatory of the United Nations Global Compact (UNGC) on human rights, labor, environment, and anti-corruption, Tetra Tech embraces the UNGC Ten Principles as part of the strategy, culture, and daily operations of our Company.

We actively engage with our stakeholders, internally and externally, to encourage input on the importance of various ESG issues to Tetra Tech and incorporate input into our strategic planning and sustainability reporting. Our annual sustainability reporting and key metrics are aligned with the priorities we have set on human capital, professional development, health & safety, and ethics. We report on human capital metrics, including gender balance, racial and ethnic diversity in our workforce, employee engagement and professional development. We have supplier programs that integrate and emphasize sustainability in the procurement of goods and services and subcontracting for our projects. We have reported annually on GHG emissions for more than a decade, significantly reducing our emissions from program inception. In 2021, we expanded our reporting and set new goals for scope 1, 2, and 3 emissions. The Science Based Targets initiative (SBTi) has approved Tetra Tech’s near-term science-based emissions reduction target. Based on input from stakeholders and in recognition of the importance of the project work we perform each year, in 2021 we also initiated our Billion People Challenge, with the overarching goal to improve the lives of one billion people by 2030. The Billion People Challenge progress is calculated each year based on our annual project impact analysis which evaluates five key metrics that are closely aligned with the Global Reporting Initiative standards and the UN Sustainable Development Goals.

Billion People Challenge Baseline and Goals

Measure

SDG

Related GRI
Performance
Indicator

2023 Additions1

Cumulative
from Baseline

2023 Goal

Lives Improved

SDG 3, 4, 5, 16

GRI 203-1; GRI 203-2

79.9 million people

625 million people

1 billion people

Project Metrics

Water

SDG 6

GRI 303-1

4.16 trillion gl/year

4.75 trillion gl

203.4 billion gl of water treated, saved, or reused

Renewable Energy

SDG 7

GRI 302-2; GRI 302-3

120,804 MW/year

138,604 MW

36,800 MW of renewable energy generated or transmitted

Ecosystems

SDG 14, 15

GRI 304-2; GRI 304-3

5.7 million ha/year

190.7 million ha

320 million ha of land and water protected, managed, or restored

Tetra Tech 2025 Proxy Statement 10

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Corporate Governance, Sustainability, and Social Responsibility

Measure

SDG

Related GRI
Performance
Indicator

2023 Additions1

Cumulative
from Baseline

2023 Goal

GHG Emission Reduction

SDG 13

GRI 305-3

52.4 million MT
CO2e/year

153.6 million
MT CO2e

10% increase from baseline annually

Social and Governance

SDG 3, 4, 5, 16

GRI 203-1; GRI 203-2

336,787 people

70.4 million
people

20% increase from baseline

1 We have seen improvement across all five metrics, principally in water and renewable energy, due to the addition of recently completed projects, including those from the RPS Group who joined us in January 2023.

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2030 target achieved

Human Capital Metrics and Goals

Measure

Related GRI
Performance
Indicator

2023 Results

Change from 2022

2023 Goals

Gender Diversity

GRI 405-1

37% of women in workforce

24,999 total headcount7
9,049 women7
15,872 men7
78 undisclosed7

No change

Gender balance of 40% women, 40% men, and 20% any gender

Gender Diversity

GRI 405-1

38% of women in management

12% increase

Gender balance of 40% women, 40% men, and 20% any gender

Racial and Ethnic Diversity

GRI 405-1

44% employees of color8

7% increase

50% employees of color8

Professional Development Training

GRI 404-2

13,843 employees participated in Tetra Tech-sponsored professional development training from baseline

9,687 additional employees participated in Tetra Tech-sponsored professional development training

15,000 employees participated in Tetra Tech-sponsored professional development training

Average Hours of Training Per Employee Per Year

GRI 404-1

14.74 average hours of training per employee in 2023

New for 2023

7 Figures exclude employees from new acquisitions, whose data is not yet integrated into Tetra Tech Human Resource systems.

8 Data is for U.S. employees only.

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Corporate Governance, Sustainability, and Social Responsibility

Operational GHG Results and Goals

Measure

Related GRI
Performance
Indicator

2023 Results

Change from 2022

2030 Goals

GHG Emissions from Operations

GRI 305-1; GRI 305-2;
GRI 305-3; GRI 305-4;
GRI 305-5

1.32 MT CO2e Scope 1
and 2 per employee

Scope 1: 12,515.90 MT CO2e

Scope 2: 22,213.16 MT CO2e

Scope 3: 41,168.08 MT CO2e3

6.9% decrease from
2021 baseline2

7.9% decrease from
2021 baseline2

16% decrease from
2021 baseline2

50% reduction in GHG emissions from 2021 baseline

Real Estate Footprint

121 square feet/employee2

16.8% decrease from
2021 baseline2

150 square feet/ employee

Renewable Energy for Utilities

GRI 302-1; GRI 302-3; GRI 302-4

53%

3.3% decrease

100% of operations use renewable sources of energy for electricity

Water Use

GRI 303-1; GRI 303-2;

GRI 303-3

1089.4 gl/employee

58% decrease

10% decrease from baseline

Use of Recycled Office Supply Products

GRI 301-1; GRI 301-2

28%

No change

50% of consumable office supplies made from recycled material

Percent of Enterprise
and Project Data
Stored in the Cloud

GRI 302-4

64%4

2% decrease

95% of enterprise and project data resides in the cloud

Energy from
Renewables by
Company’s Cloud
Vendors

GRI 302-4

97%

35% increase

100% cloud data serviced by renewable energy

Enterprise Supply
Chain Vendors Vettedfor
Cybersecurity
Standards

GRI 302-4

85%

52% increase

100% enterprise supply chain vendors vetted for cybersecurity standards

Enterprise Platforms
Evaluated for
Accessibility

GRI 417-1

91%

No change

100% enterprise platforms evaluated for accessibility

2 GHG comparison is to the recalculated 2021 baseline which includes data from RPS businesses that were acquired in January 2023.

3 Scope 3 data set expanded in 2023.

4 Figure includes data from RPS businesses acquired in January 2023 and not yet migrated to Tetra Tech’s cloud data storage. Tetra Tech data storage—excluding RPS figures for 2023—was 73%, a 13% increase over 2022.

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Our Sustainability Program is led by our Chief Sustainability Officer, who has been appointed by our Board of Directors and is supported by corporate and operations representatives through our Sustainability Council. We continuously review sustainability-related policies and practices, integrate input from stakeholders, and assess the results of our efforts in order to make future improvements. Tetra Tech’s Board of Directors reviews and approves the Sustainability Program and evaluates our progress in achieving the goals and objectives outlined in our plan. As part of our membership in the UNGC, we annually report on the Communication

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on Progress using Tetra Tech’s Sustainability Report. In 2024, we moved to the #8 position on Barron’s 100 Most Sustainable U.S. Companies list and received Climate Change Business Journal and Environmental Business Journal awards for outstanding business and advancing climate resilience, innovation, and diversity and inclusion.

Corporate Social Responsibility

Tetra Tech seeks clear, sustainable solutions that improve the quality of life for everyone.

Our professionals are encouraged to participate in outreach programs to help improve the communities in which they live and work. Tetra Tech employees and offices around the globe participate in many financial, in kind, volunteer, and pro bono activities each year. In 2024 we advanced our commitment to Leading with Science® through our Science, Technology, Engineering, and Mathematics (STEM) Program to help shape the next generation of innovators and problem solvers. As a supporter of the nonprofit humanitarian organization Engineers Without Borders, we are committed to helping communities in developing countries meet their basic human needs through lasting, scalable projects and technologies.

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Tetra Tech brings together engineers and technical specialists from all backgrounds to solve our clients’ most challenging problems. At the end of FY 2024, we had 30,000 employees worldwide. A large percentage of our employees have technical and professional backgrounds and undergraduate and/or advanced degrees. Our professional staff includes, but is not limited to, analysts, archaeologists, architects, biologists, chemical engineers, chemists, civil engineers, computer scientists, data scientists, digital engineers, economists, electrical engineers, environmental engineers, environmental scientists, geologists, hydrogeologists, mechanical engineers, oceanographers, project managers, software engineers, statisticians, and toxicologists.

Health and Safety

We are committed to providing and maintaining a healthy and safe work environment for our employees. We provide training to employees to support the safe execution of their work and improve their understanding of behaviors that can be perceived as discriminatory, exclusionary, and/or harassing and provide safe avenues for employees to report such behaviors. We implement best practices and comply with local regulatory requirements. Our people understand acceptable workplace behavior as covered in our Corporate Code of Business Ethics and Conduct. Further, as health and safety has always been a fundamental value at Tetra Tech, we report on two standard metrics: Lost Workday Incident Rate (LWDIR) and Total Recordable Incident Rate (TRIR). We have added two metrics that measure employee engagement in our H&S outreach programs and trainings and developed goals for these metrics, as reported in our 2024 Sustainability Report.

Health and Safety Results and Goals

Measure

Reltated GRI
Performance
Indicator

2023 Results

Change from 2022

2030 Goals

Lost Workday Incident Rate (LWDIR) and Total Recordable Incident Rate (TRIR)

GRI 403-2

LWDIR 0.08, 73% better than industry average6

TRIR 0.24, 73% better than industry average6

9% increase

3% increase

Continual improvement toward achieving and maintaining a zero LWDIR and a TRIR better than the industry average6

Employee Participation: Safety Month Outreach

GRI 403-5

1,466,599 engagements

32% increase

10% increase from baseline

Employee Participation: Training Completed

GRI 404-6

60,412 H&S-related training modules completed by employees

33% increase

10% increase from baseline

5 H&S metrics are based on operational entities as defined for incident tracking.

6 NAICS Code 54 Professional, Scientific, and Technical Services, BLS Data 2022

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We believe supporting a safe and inclusive workplace is everyone’s responsibility in every office and on every project. In 2023, the most recent year for which full year data is available, our enterprise-wide TRIR was 0.24, which is 73 percent better than the industry average, and LWDIR was 0.08, which is 73 percent better than the industry average. In 2024 employees completed approximately 90,000 health and safety-related training modules in multiple languages. In addition, multiple Tetra Tech operating units achieved the US National Safety Council Perfect Record award criteria for working at least 12 consecutive months without incurring an occupational injury or illness that resulted in days away from work. This achievement represented over 33 million hours worked without a lost work day event. Furthermore, our 2024 Safety Month campaign saw over 1.8 million engagements across all internal and external platforms.

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Diversity, Equity, Inclusion & Accessibility

With a highly collaborative workforce of thousands of high performing individuals working from hundreds of offices around the world, Tetra Tech truly is a multinational, multicultural organization. We value the diversity, perspectives and experiences that our employees bring to their engagement with co-workers and to their appreciation of our clients’ needs and objectives.

Tetra Tech has received recognition for its Diversity, Equity, Inclusion & Accessibility (DEIA) program and company culture that promote a working environment and community where employees are valued for their contributions including Newsweek’s designation of Tetra Tech as one of “America’s Greatest Workplaces for Diversity for 2024,” receiving the organization’s highest ranking.

Our DEIA Policy guides the Board of Directors, management, employees, subcontractors, and partners in providing an inclusive culture. Our DEIA Council monitors Tetra Tech’s diversity, equity, inclusion, and accessibility practices and makes recommendations to the Board and CEO for any changes or improvements to our program. The DEIA Council includes representatives from across the Company who reflect the diversity and values of our employees.

Tetra Tech values diversity, equity, inclusion, and accessibility and undertakes various efforts throughout our operations to promote these initiatives. We have set goals for diversity and gender that are reported in our 2024 Sustainability Report.

We promote DEIA through key programs including:

•

Equal employment opportunity—Tetra Tech ensures that our practices and processes attract a diverse range of candidates and that candidates are recruited, hired, assigned, developed, and promoted based on merit and their alignment with our values.

•

Enhancing learning and development opportunities—To support our employees in reaching their full potential, Tetra Tech offers a wide range of internal and external learning and development opportunities. Education assistance is offered to financially support employees who seek to expand their knowledge and skill base.

DEIA-relevant training is required for all Tetra Tech employees as part of our company-wide ethics and compliance program. This relevant training educates all employees on how to manage bias through the employment relationship, as well as avoiding offensive behavior and workplace harassment. Above and beyond this required training, Tetra Tech has built a DEIA training resource library that includes online courses that enable all employees to gain insights into DEIA perspectives and learn individual behaviors that can foster a more inclusive and accessible environment. Tetra Tech’s DEIA training library is available to all employees.

Tetra Tech also provides DEIA trainings and webinars throughout the year to foster and reinforce a culture of inclusivity. We educate hiring managers and employees on myriad forms of unconscious bias. For example, we provide guidance on how to recognize and avoid gendered language in our internal and external communications, as well as how to maximize digital accessibility so that content can be used by disabled people as easily as by non-disabled people.

•

Employee Resource Groups—As part of Tetra Tech’s commitment to a culture of inclusion, our Employee Resource Groups (ERGs) broaden and enhance companywide interaction opportunities for our employees. Tetra Tech’s global ERG program supports our employees and creates collaborative teams, or ERGs, where all voices are heard, all employees feel safe, and each employee has the opportunity to thrive. Our ERGs are open to all and involve activities for both employees whose background is the focus of the ERG and those who are supportive of the group (also known as allies). These global networks build on and coordinate with the many local networks already active throughout our operations and include groups focused on the experiences of Black, Latino/Hispanic, Pan-Asian, Women, Veterans, Disabled, LGBTQIA+ employees, and emerging professionals. Through our ERGs, we have established partnerships with the National Society of Black Engineers, Society of Hispanic Professional Engineers, Wounded Warrior Project, Association for Black & Minority Ethnic Engineers (UK), Business Disability Forum (UK), Inclusive Employers (UK), and We Are PoWEr (UK). Our DEIA Council charters and guides the development of the global ERGs to support our thriving worldwide employee community.

•

Tetra Tech Partners—Tetra Tech’s DEIA practices have also been effective at broadening engagement with minority- and women-owned enterprises (MBE/WBEs), including indigenous peoples. Tetra Tech’s Small Business Council functions to identify diverse and disadvantaged businesses with qualifications that can add value to our global projects. Tetra Tech is a five-time winner of the U.S. Small Business Administration’s prestigious Dwight D. Eisenhower Award for Excellence for our effective small business subcontractor program. Our robust supply chain enables us to engage with small, local, and diverse enterprises across all socioeconomic categories, including MBEs, WBEs, small-disadvantaged businesses, and Historically Black Colleges and Universities/Minority Institutions (HBCU/MI). Tetra Tech is also active in the U.S. Small Business Association’s mentor-protegee program, where we work to develop and mentor minority or disadvantaged business. Tetra Tech has several protégés

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including an Alaskan Native Corporation 8a Business, a Woman-Owned Small Business, and a Service-Disabled Veteran-Owned Small Business. In addition, Tetra Tech partners with the U.S. Department of Defense SkillBridge program and UK Defence Employee Recognition Scheme (ERS) to support service members’ move from military to civilian life, and has been awarded Gold status under the ERS.

For additional information, visit our website at tetratech.com/diversity.

Professional Development

Tetra Tech invests in the continuing professional development of all our employees. This investment enables us to attract and retain the caliber of talent that is integral to our success as a high-end professional consulting and engineering company that is Leading with Science®, and we have one of the lowest employee turnover rates in our industry.

Professional development is essential to the successful performance of high-end projects and collaborative multidisciplinary team delivery of responsive solutions. Working on challenging, innovative, and technically cutting-edge projects enhance our employees’ professional development and growth. Our work encompasses many sustainable, societal, and beneficial outcomes that enable our employees to make positive contributions that benefit society. Technically innovative projects also provide an opportunity for our employees to “advance the science” in leading applications of our expertise to water, environment and sustainable infrastructure. We encourage our employees to develop patents, where appropriate, and to publish journal articles in their field of expertise, often in collaboration with our clients. With our 550 offices worldwide, our employees can meaningfully contribute to improving the quality of life for the communities in which they work and live.

The Tetra Tech Academy provides access to all employees to training, technical exchange and collaboration, and skill development resources through its customized Learning Management System, providing professional development opportunities for employees at all levels of the company throughout their careers. Technology skills development includes access to a series of live webcasts and recorded technology transfer sessions. Company-wide networking events provide interactive skills development activities. Employees are also provided with access to training in leadership development, project management skills, and interpersonal skills development. The wellbeing of all our employees is a unifying theme across our business. For instance, we hold an annual month-long wellness challenge which encourages and enables participation from colleagues with all levels of fitness and ability to take part in various wellness activities. Our Corporate Information Technology team provides software training and skills development modules as well as cyber security training to all employees. Tetra Tech also supports and provides funding for our employees to achieve discipline specific training, certifications, and accreditation programs across the Company. Programs such as specific health and safety programs, hazardous waste investigation, environmental certifications, and professional certifications are encouraged as per client, project and professional development needs.

In addition, we have specific focused programs which are designed, taught, and facilitated by accredited external resources as well as Tetra Tech leadership, technical experts, and experienced program managers. These programs include:

•

Leadership Academy—Tetra Tech’s Leadership Academy develops our high potential employees from around the world into outstanding business leaders. Instructors for this intensive, year-long program are executive management and operational leaders from within the Company. Participants are immersed in all aspects of the operations of the Company and complete challenging, real-world assignments designed to hone their leadership and management skills. Completion is personally certified by the Company’s CEO and Chairman of the Board.

•

Project Management Training Program—Tetra Tech develops project managers who are world class in their abilities and performance. Tetra Tech’s Project Excellence Steering Committee (PESC) sponsors the development and implementation of our comprehensive Project Management Training Program. The training program has been designed to address all areas of the project life cycle. Tetra Tech’s Project Management Training Program is available to all employees and is focused on professional development, techniques for managing high-end projects and how to employ enterprise systems, dashboards and proprietary technology tools. Our Project Management Training Program provides comprehensive training in high-end project leadership skills through on-line training, virtual workshops, and in-person events, where attendees progress through three development tiers.

•

Executive Development Initiative—Tetra Tech further develops our senior-level leaders into effective, well-rounded executives. Participants complete a variety of assessments, including 360 reviews, and engage in extensive career development mentoring, which result in development goals and opportunities for greater engagement throughout the Company and leadership of our employees around the world.

•

Fearless Entrepreneur Program—Tetra Tech develops employees into client oriented, business minded professionals who are driven to understand and meet the needs of our clients. Through this company-wide program, developing professionals

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are challenged and mentored through a process of building client relationships. Participants take part in group discussions in a classroom setting and then are required to implement learned strategies with actual and potential clients. This program is led by senior operations management and completion is certified by an executive officer of the Company.

•

Employee Resource Group (ERG) Sponsored Training—ERGs provide training, networking, and mentoring opportunities accessible to all Tetra Tech employees. For example Tetra Tech’s Professional Women’s Network provides a monthly platform for issues that affect women in the workplace. Tetra Tech women at various levels of leadership share insights and knowledge acquired throughout their careers. This group provides the opportunity for women at any stage in their careers to ask questions and further their career development by connecting them with mentors across the Company. We also actively participate in a number of DEIA forums aligned with our professional memberships or sectors of operation such as Women in Nuclear and Women in Project Management.

•

Tetra Tech Technology Transfer (T4) and ToolTalk Webcast Series—Tetra Tech holds technology focused webcasts accessible to all employees around the world, to provide information and resources to improve their use of available internal tools and develop their technical skills. Through the T4 and ToolTalk Webcast Series, Tetra Tech experts and academics present and lead discussions about new technologies and programs, best practices, and opportunities for growth across the Company. All employees are invited to participate in the live presentations or view webcast recordings, ensuring that we are growing the knowledge, strength, and leadership of our employees around the world.

•

Tech 1000 Challenge—The Tech 1000 Challenge is a competition among one thousand of the company’s staff to create the most innovative, technology focused solution to a real client challenge. The event brings together employees from around the world to team up and vie for the top technology solutions that address our clients’ needs. Participants from across our markets form teams to focus on client needs, receive briefings on our Tetra Tech Delta technologies and artificial intelligence (AI) tools from their peers, and hone their skills in designing strategies and pitching client solutions. Participants are provided in-depth training on technology, marketing, branding, tools development, and software business practices. Top ranked teams also receive mentoring and support to further develop their ideas. Access to technology briefings and tools is provided to all employees as a result of the challenge event.

•

Discipline Specific Training and Accreditation—Tetra Tech supports our employees in discipline specific training, certifications, and accreditation programs across the Company. Programs such as specific health and safety programs, hazardous waste investigation, environmental certifications, and professional certifications are encouraged as per client, project and professional development needs.

•

Tetra CONNECT—Tetra Tech holds an annual companywide event available to all employees to celebrate our achievements, build relationships, gain knowledge to advance our skills, enhance our projects, and strengthen our culture. The event features panel discussions about our projects, workshops highlighting the most exciting technology tools in our industry, networking opportunities to meet colleagues from across the world, skills labs to hone technical and management skills, and other programming focused on the Company and who we are. In addition, the event celebrates our annual excellence and achievement award winners in project management, technical achievement, marketing and business development, health and safety, community service, and DEIA, stories of innovation and dedication from employees in a TED talk-like format, and how we are improving lives through Tetra Tech’s long-standing partnership with Engineers Without Borders.

By offering our employees meaningful work and continuous career development opportunities, Tetra Tech is well positioned to continue our growth through recruitment, development, and retention of the best talent in the industry.

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Our Board of Directors

Our Board of Directors is responsible for overseeing, counseling, and directing management in serving the long-term interests of our Company and stockholders, with the goal of building long-term stockholder value and ensuring the strength of our Company for our clients, employees, and other stakeholders. In this capacity, the Board’s primary responsibilities include establishing an effective Corporate Governance Program with a board and committee structure that ensures independent oversight; overseeing our business, strategies (including mergers and acquisitions), and risks; maintaining the integrity of our financial statements; evaluating the performance of our senior executives and determining their compensation; undertaking succession planning for our CEO, other senior executives, and directors; and reviewing our Annual Operating Plan (AOP) and significant strategic and operational objectives and actions.

Board Composition

Our bylaws provide that our Board shall consist of between five and 10 directors, with the exact number fixed from time to time by Board resolution. We believe a limited number of directors helps maintain personal and group accountability. The Board currently consists of seven members. Our Board is majority independent in composition and outlook. All our current directors have been nominated for election by the Board of Directors upon recommendation by the NCG Committee.

Board Meetings and Attendance

During FY 2024, our Board of Directors held six meetings. During that period, all the incumbent directors attended or participated in at least 75% of the total number of meetings of the Board and of the committees of the Board on which each of those directors served during the period for which each of them served. Our directors are strongly encouraged to attend the 2025 Annual Meeting, and all directors then in office attended the 2024 Annual Meeting.

Corporate Governance Policies

Our corporate governance policies, listed in the following table, are reviewed at least annually and amended from time to time to reflect the beliefs of our Board, changes in regulatory requirements, evolving best practices, and recommendations from our stockholders and advisors.

Corporate Governance Policies

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Our Board of Directors

Director Independence

Upon recommendation of the NCG Committee, our Board of Directors has determined that Mr. Birkenbeuel, Mr. Douglas, Mr. Gandhi, Ms. Obiaya, Dr. Ritrievi, and Ms. Volpi are each independent under the criteria established by Nasdaq for director independence. The Board also determined that Ms. Joanne Maguire, who retired from the Board on September 30, 2024, was independent under the criteria established by Nasdaq for director independence. Ms. Maguire also served on the Nominating and Corporate Governance Committee and Compensation Committee during FY24. The Board determined that Ms. Maguire satisfied the independence requirements to serve on each committee. Mr. Batrack is not independent because he is serving as our CEO.

All members of our Audit, Compensation, and NCG committees are independent directors. In addition, the members of the Audit Committee and Compensation Committee each meets the additional independence criteria required for membership on those committees under applicable Nasdaq listing standards. The Board also has determined that each member of the Audit Committee qualifies as an “audit committee financial expert” under SEC rules.

Board Leadership Structure

Our Board of Directors does not have a policy with respect to whether the roles of Chairman and CEO should be separate or combined. We currently have a combined Chairman/CEO role as well as an independent Presiding Director. We believe that the combined Chairman/CEO role is appropriate because it allows for one individual to lead our Company with a cohesive vision, the ability to execute that vision, and the understanding of the significant enterprise risks that need to be mitigated or overcome to achieve that vision. It also fosters clear accountability, effective decision making, and alignment on corporate strategy. Combined leadership at the top also provides the necessary flexibility for us to rapidly address the changing needs of our business.

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Our Board of Directors

Balancing our combined Chairman/CEO is our Presiding Director, who is independent and has critical duties to ensure effective and independent oversight of Board decision making. The Board has determined that the role of Presiding Director will rotate to ensure independence and will be elected annually, with a maximum term of four years. At a meeting in July 2024, the independent directors elected Ms. Volpi to serve as Presiding Director.

Our governance policies describe the Presiding Director’s duties, which delineate clear responsibilities to ensure independent stewardship of our Board, as summarized below.

	Presiding Director Roles and Responsibilities
	• Schedule meetings of the independent directors • Chair separate, executive session meetings of the independent directors • Serve as principal liaison between independent directors and Chairman/CEO • Communicate with Chairman/CEO and disseminate information to remaining directors as appropriate • Provide leadership to the Board of Directors if circumstances arise in which the role of the Chairman may be, or may be perceived to be, in conflict with the Company • Be available, as appropriate, for consultation and direct communication with major stockholders • Oversee, with the NCG Committee, the annual self-evaluation of the Board

Supplementing the Presiding Director are our committee chairs and members, all of whom are independent. With the Compensation Committee conducting a rigorous annual evaluation of the CEO’s performance, which is discussed by all independent directors during executive sessions, we believe our Board leadership structure provides independent oversight of our Company.

Board Committees

Each of our Board committees has a separate written charter that describes its purpose, membership, meeting structure, authority, and responsibilities. These charters, which can be found in the ESG Governance Overview section of our website at investor.tetratech.com/esg/governance-overview, are reviewed annually by the respective committee, with any recommended changes adopted upon approval by the Board.

The Board has three standing committees consisting solely of independent directors, each with a different independent director serving as chair of the committee. Our standing committees are the Audit Committee, the Compensation Committee, and the NCG Committee. Board committee meetings are held sequentially (i.e., committee meetings do not overlap with one another) and enable each of our Board members to attend each committee meeting. We believe this practice is highly beneficial to our Board specifically and to the Company in general because each of our Board members is aware of the detailed work conducted by each Board committee. This practice also affords each of our Board members the opportunity to provide input to each committee before any conclusions are reached.

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Our Board of Directors

The primary responsibilities, membership, and meeting information for our three standing committees are summarized below.

Standing Committees of the Board of Directors

	Audit Committee
	Meetings in FY 2024: 4			Average Attendance in FY 2024: 100%
	Chair Gary R. Birkenbeuel Members Kimberly E. Ritrievi Kirsten M. Volpi All members satisfy the audit committee experience and independence standards required by Nasdaq and have been determined to be financially literate. Each member of the Audit Committee has been determined to be an “audit committee financial expert” under applicable SEC regulations.			Responsibilities • Review our significant accounting principles, policies, and practices in accounting for and reporting our financial results under generally accepted U.S. accounting principles • Review our annual audited financial statements and related disclosures • Review management letters or internal control reports and review our internal controls over financial reporting • Review the effectiveness of the independent audit effort • Appoint, retain, and oversee the work of the independent accountants • Pre-approve audit and permissible non audit services provided by the independent registered public accounting firm • Review our interim financial results for each of the first three fiscal quarters • Review management’s analysis of significant accounting issues, changes, estimates, judgments or unusual items relating to financial statements and critical accounting policies • Be directly responsible for our internal Management Audit Department, approve its audit plan, and review its reports • Review and discuss financial, liquidity, tax and treasury, litigation, and Sarbanes Oxley Act of 2002 compliance matters in accordance with our enterprise risk management (ERM) policy • Oversee compliance audit of our ERM program implementation • Review our programs to manage, monitor and mitigate significant business risks, including cyber security risks • Review and oversee related party transactions • Review our ethics and compliance program • Review all hotline complaints relating to accounting, internal controls, or auditing matters • With the Compensation Committee, approve the compensation of our CFO • Review and establish procedures for receipt, retention, and treatment of complaints regarding accounting, internal controls, auditing, and related matters • Prepare the annual Audit Committee Report to be included in the proxy statement • Meet at least quarterly with the independent accountants, and if necessary, the CFO or a member of the Management Audit Department

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Our Board of Directors

	Nominating and Corporate Governance Committee
	Meetings in FY 2024: 4			Average Attendance in FY 2024: 100%
	Chair Prashant Gandhi Members Gary R. Birkenbeuel John M. Douglas All members satisfy the independence standards required by Nasdaq.			Responsibilities • Develop criteria for nominating and appointing directors, including board size and composition; corporate governance policies; and individual director expertise, attributes, and skills • Recommend to the Board the individuals to be nominated as directors • Recommend to the Board the directors to be selected for service on the Board committees • Develop, annually assess, and make recommendations to the Board concerning appropriate corporate governance policies • Oversee an annual review of the performance of the Board and each committee and report the results thereof to the Board • Review annually the adequacy of the committee charters and recommend to the Board proposed changes • Support the Board in reviewing succession plans relating to the positions held by executive officers and directors • Review our Corporate Code of Business Ethics and Conduct and anti-fraud policies in accordance with our ERM policy; and consider any conflict-of-interest issues between the Company, its directors or executive officers • Review all non-financial hotline complaints • Consider any conflict of interest issues between the Board or executive officers and the Company

	Compensation Committee
	Meetings in FY 2024: 4			Average Attendance in FY 2024: 100%
	Chair Kirsten M. Volpi Members Christiana Obiaya Kimberly E. Ritrievi All members satisfy the independence standards required by Nasdaq. All members qualify as “nonemployee directors” under Rule 16b-3 of the Exchange Act.			Responsibilities • Review and approve the annual base salaries and annual incentive opportunities of the CEO and other executive officers, including an evaluation of the performance of the executive officers in light of our performance goals and objectives • Review and approve all other incentive awards and opportunities, any employment agreements and severance arrangements, any change in control agreements, and any special or supplemental compensation and benefits as they affect the executive officers • Review and discuss comments provided by stockholders and proxy advisory firms regarding our executive compensation • Monitor compliance with requirements under the Sarbanes Oxley Act of 2002 relating to loans to director and executive officers, and with all other applicable laws affecting employee compensation and benefits • Oversee our compliance with SEC rules and regulations regarding stockholder approval of certain executive compensation matters • Review director and executive officer stock ownership under our stock ownership guidelines • Make recommendations to the Board on changes in the compensation of nonemployee directors • Review and discuss incentives and rewards in accordance with our ERM responsibility matrix • Make recommendations to the Board with respect to incentive-based compensation plans, equity-based plans, and executive benefits • Review and approve all grants of equity awards • Review and discuss the annual Compensation Discussion and Analysis and Compensation Committee Report to be included in the proxy statement • Select, retain and work with the independent compensation consultant

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Our Board of Directors

Executive Sessions

Our Board believes it is important to have executive sessions without our CEO being present, which are scheduled after every regular meeting of the Board. Our independent directors have robust and candid discussions at these executive sessions during which they can critically evaluate the performance of our Company, CEO, and management.

In addition, executive sessions of the Audit Committee are scheduled following each regular meeting of the Audit Committee (with our independent auditors, with the head of our internal audit department, and with executive management, if deemed necessary). An executive session of the Compensation Committee is scheduled following the Compensation Committee meeting each November, at which executive compensation determinations are made. The NCG Committee also holds executive sessions at its discretion.

Oversight of Risk Management

Enterprise Risk Management and Strategic Risks

We believe that risk is inherent in the pursuit of long-term growth opportunities. Our management is responsible for day-to-day risk management activities. The Board of Directors is responsible for the oversight of our risk management. With this oversight, we have implemented an Enterprise Risk Management (ERM) program with practices and policies designed to help manage the risks to which we are exposed in our business and to align risk taking appropriately with our efforts to increase stockholder value.

Our Corporate Risk Management Officer reports the status of the ERM program to the Board on a semiannual basis, in addition to quarterly reports to the Audit Committee. The reports address our risk management effectiveness, projects that might significantly impact our financial condition, and any new risk issues and mitigation measures that have been implemented. The Board receives regular updates from our Chief Information Officer on the overall cybersecurity risk environment, including our Company’s enterprise-wide cybersecurity governance, risk assessment results and key initiatives.

Other committees of the Board oversee certain categories of risk associated with their respective areas of responsibility to better coordinate with management and serve the long-term interests of our stockholders. The reports the Board receives from the committees covering topics discussed at their meetings include any discussion of the areas of risk overseen primarily by each committee.

In addition, the Board participates in regular discussions with our senior management on several core subjects in which risk oversight is an inherent element, including strategy, operations, finance, mergers and acquisitions (M&A), and legal matters. The Board believes the leadership structure described in the Board Leadership Structure section on page 20 of this proxy statement facilitates the Board’s oversight of risk management because it allows the Board, with leadership from the Presiding Director and working through its committees, to participate actively in the oversight of management’s actions.

Major Areas of Oversight of the Board and Standing Committees

Risks Associated with Compensation Policies and Practices

As described in the Compensation Discussion and Analysis section on page 39 of this proxy statement, we maintain what we believe are best practices in compensation and corporate governance that collectively encourage ongoing risk assessment and mitigation.

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Our Board of Directors

The Compensation Committee regularly reviews our executive compensation program to ensure it does not provide incentives that encourage our employees to take excessive risks in managing their respective business or functional areas. Our compensation program includes the following safeguards:

•

The program balances executive retention with rewarding stockholder value creation

•

The majority of executive compensation is at risk, with a mix consistent with market practices and primarily equity based to promote long-term performance and long-term decision making

•

The incentive mix is balanced, with short- and long-term performance metrics that do not overlap, cover different time periods, and are balanced among annual financial objectives and long-term economic and stockholder value creation

•

Our annual incentive plan (AIP) and LTIs appropriately balance profitable growth in the near term with sustainable long-term financial success, use multiple performance metrics, measure performance at multiple levels (corporate, business group, and individual), and provide realized compensation based primarily on our performance

•

The Compensation Committee may exercise discretion to adjust the objective, formulaic AIP awards based on individual performance

•

AIP payouts are not guaranteed and are subject to maximum payout caps

•

Our incentive metrics and performance goals have multiple approval and oversight levels, including approval by members of the Compensation Committee

•

Our performance stock unit (PSU) awards have overlapping performance periods, are performance based, use multiple performance metrics, are subject to maximum payout caps to encourage appropriate performance focus and to limit potential risk taking, and cliff vest at the end of three years

•

Our change of control plan is market aligned, with change of control benefits provided on a double trigger basis that do not provide excessive incentive to seek a transaction and are not grossed up for excise taxes

•

Our clawback policy and stock ownership guidelines are consistent with market practices and aligned with regulatory requirements (where applicable)

•

Our stock ownership guidelines, annual stock awards, and vesting provisions create sustained and consistent ownership stakes

Based on these and other factors as well as on the advice of its independent compensation consultant, the Compensation Committee has concluded that our compensation policies and practices strike an appropriate compensation risk balance, do not encourage excessive risk taking, and do not as a whole create risks that are reasonably likely to have a material adverse effect on our Company.

Succession Planning

Our Board is involved in the identification and cultivation of our future leaders. We maintain an annual performance review process and leadership development program for our key employees. Management develops leadership at all levels of our organization by identifying core talent, cultivating the skills and capabilities that will allow identified individuals to become our future leaders, assessing their development, and identifying gaps and developmental needs in skills and experience. At its meetings, the Board has the opportunity to meet with leaders and employees throughout our Company, including business group leaders and employees in finance, law, information technology, risk management, strategy health and safety, and human resources.

The Board is responsible for conducting executive succession planning annually, including progress in current job position and career development in terms of strategy, leadership, and execution. During this review, the CEO and the independent directors discuss future candidates for senior leadership positions, succession timing for those positions, and development plans for the candidates with the highest potential. This process ensures continuity of leadership over the long term and forms the basis on which we make ongoing leadership assignments. In addition, the NCG Committee is responsible for conducting director succession planning and the selection of director nominees as discussed below.

Director, Board, and Committee Evaluations

The NCG Committee oversees and conducts an annual evaluation of our directors, Board, and Board committees. For the Board, the comprehensive self-assessment covers areas such as effectiveness, composition, culture, resources, and meetings. Each of the topics is scored from 1 (Needs Improvement) to 5 (Role Model), with 3 being Acceptable. As part of this process, the Presiding Director

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Our Board of Directors

also has an individual conversation with each director to discuss their qualitative comments and thoughts. The Board then discusses each topic, with a particular focus on any topic that has received a score of 3 or less from any director.

The directors also comment on the Board’s most significant contributions to the Company during the last 12 months, the most important issues for the Board to address in the next 12 months, and any areas in which the Company could improve the Board’s management practices. Those comments result in action items that are placed on the agenda and addressed in subsequent Board meetings.

For each of the committees, the self-assessment covers areas such as committee composition, effectiveness, structure, information and resources, and meetings. As with the Board self-assessment, each of the areas is scored from 1 to 5. The members of the committee also comment on the committee’s greatest contribution to the Company during the last 12 months and the most important issues for the committee to address in the next 12 months. The chair of each committee then leads a discussion of each area among the committee members, with a particular focus on any area that has received a score of 3 or less from any committee member. The comments result in action items that are placed on the agenda and addressed in subsequent committee meetings.

Many of the improvements in our corporate governance practices and board and committee processes have resulted from this annual evaluation process. Our Board views the annual evaluation process as an integral part of its commitment to cultivating excellence and best practices in its performance.

Selection of Director Nominees

Director nominees are generally recommended to the Board by the NCG Committee for election to the Board. Our Board believes that the backgrounds and qualifications of our directors, considered as a group, provide a mix of complementary experience, knowledge, and abilities that enables our directors to effectively fulfill their oversight responsibilities.

In considering whether to recommend a candidate as a director nominee, the NCG Committee applies the criteria described in our governance policies, including independence, integrity, high personal and professional ethics, sound business judgment, and the ability and willingness to commit sufficient time to the Board. In evaluating the suitability of individual Board members, the NCG Committee takes into account many factors, including a general understanding of business development and strategy, risk management, finance, financial reporting, and other disciplines relevant to the success of a publicly traded company in the then current business environment; understanding of our business and the issues affecting it; relevant education and professional background; personal accomplishment; and diversity. The NCG committee does not have a formal policy specifying how diversity of background and personal experience should be applied in identifying or evaluating director candidates, and a candidate’s background and personal experience, while important, does not necessarily outweigh other attributes or factors the NCG Committee considers in evaluating candidates. However, the Board of Directors is committed to identifying candidates with gender, racial and/or ethnic diversity. The NCG Committee does not assign specific weights to the criteria, and no particular criterion is necessarily applicable to all nominees.

In recommending candidates for election to the Board of Directors, the NCG Committee considers nominees recommended by directors, officers, stockholders, and others using the same criteria to evaluate all candidates. The NCG Committee reviews each candidate’s qualifications, including whether the candidate possesses any of the specific qualities and skills desirable in members of the Board of Directors. Evaluations of candidates generally involve a review of background information, internal discussions, and interviews with selected candidates as appropriate. Upon selection of a qualified candidate, the NCG Committee recommends the candidate for consideration by the full Board. The Committee may engage consultants or third-party search firms to assist in identifying and evaluating potential nominees.

Stockholder Submission of Director

Stockholders may recommend director candidates by submitting candidates’ names, together with their qualifications, to NCG Committee Chair, c/o Corporate Secretary, Tetra Tech, 3475 E. Foothill Boulevard, Pasadena, California 91107. To be considered at the 2026 Annual Meeting, stockholder nominations must comply with the notice procedures and other requirements of our bylaws as described under “Submission of Stockholder Items for 2026 Annual Meeting” in the Meeting and Voting Information section of this proxy statement.

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Director Qualifications

Qualifications that are particularly desirable for our directors to possess in order to provide oversight and stewardship of our Company include those listed in the table.

Desirable Director Qualifications

Qualification	Description	Value to Our Board and Stockholders
Senior Leadership Experience	Service in a senior executive position	Provides us with valuable external perspectives with which to assess our operations, execute our strategies, mitigate related risks, and improve our policies and procedures.
Industry and Technical Expertise	Experience in consulting and engineering and related services	Allows us to better understand the needs of our clients in developing our business strategies as well as to evaluate acquisition and divestiture opportunities.
Government Client Regulatory Experience	Service in a position that requires interaction with government clients	Provides us with experience and insight into working constructively with government agencies and administrators and addressing significant public policy and regulatory compliance issues in areas related to our business and operations.
Business Development and M&A Experience	Background in business development and in the analysis of proposed M&A transactions	Provides us with insight into developing and implementing strategies for growing our business through combinations with other organizations, including analyses of the “fit” of a proposed acquisition with our Company’s strategy, the valuation of the transaction, and the management plan for integration with existing operations.
Financial Sophistication	Understanding of accounting, auditing, tax, banking, insurance, or investments	Helps us oversee our accounting, financial reporting, and internal control processes; manage our capital structure; optimize capital allocation; and undertake significant transactions.
Public Board Experience	Prior or concurrent service on other SEC reporting company boards	Demonstrates understanding of the extensive and complex oversight responsibilities of directors and helps reinforce management accountability for maximizing long-term stockholder value. Also provides insights into a variety of strategic planning, compensation, finance, and governance practices.
Innovation / Technology Experience	Domain expertise and skill, technology/innovation, and practical experience with tech transformation and disruption	Allows us to better understand and anticipate technical trends, generate disruptive innovation, and extend and create new business models.
International Operations Experience	Experience with global companies, especially those with operations in Australia, Canada and Europe	Provides us with insight into the conduct of global operations, including an understanding of diverse business environments and economic conditions and cultures and a broad perspective on global business opportunities.
Risk Oversight Experience	Practical experience in risk governance, ERM framework, and knowledge/understanding of risk monitoring and mitigation, including cybersecurity	Helps us understand ERM program structures as well as practices and policies designed to identify and manage risks and to properly align risk taking with overall governance and operations.
Talent Management / Compensation Experience	Practical experience developing, managing, motivating, and compensating employees	Provides us with insight into cultivating an inclusive culture consistent with our values and purpose, providing an engaging work environment, attracting top talent, investing in our employees, supporting their career development, and remaining competitive in the marketplace.

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Our Board of Directors

The graph below shows the qualifications of our FY 2025 director nominees.

Board Refreshment

Our governance policies reflect our belief that board refreshment is achieved through a variety of practices. In particular, the Board has set the maximum tenure for non-employee directors at 12 years, except that the maximum tenure is 15 years for directors whose service began prior to 2014 to facilitate the transfer of institutional knowledge and provide for productive board refreshment upon adoption of the tenure requirement. Tenure limits serve to facilitate fresh ideas and viewpoints being consistently brought to the Board, while still allowing sufficient time for directors to develop insight into our strategies, operations, and risks and to provide valuable contributions to Board deliberations.

We have adopted the policies shown in the table below to facilitate refreshment of our Board and ensure that it continues to appropriately challenge our management.

Policies Supporting Board Refreshment

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The graph below shows the tenure of our FY 2025 independent director nominees.

Director Diversity

The NCG Committee focuses on skills, expertise, and background to complement the existing Board in light of the diverse and global nature of our business and operations. Women comprise almost half of our director nominees and two nominees identify as racial or ethnic minorities.

Active Stockholder Engagement and Communication Policy

Governance Engagement

We value our stockholders’ opinions about our governance policies and practices and actively solicit input through our stockholder engagement program. In advance of the 2025 Annual Meeting, we proactively contacted our largest institutional stockholders, representing a majority of our then outstanding shares, to solicit their views on our corporate governance, executive compensation programs, and ESG. We welcome feedback on our Corporate Governance Program that this active and ongoing engagement with stockholders provides.

Contacting the Board

Stockholders may contact our Board, Chairman, Presiding Director, any committee or committee chair, or any other individual director concerning business related matters by writing to Board of Directors (or a particular subgroup or individual director), c/o Corporate Secretary, Tetra Tech, 3475 E. Foothill Boulevard, Pasadena, California 91107 or via email to TES.AskTheBoard@tetratech.com.

All such communications will be reviewed by the Secretary or their designee for the sole purpose of determining whether the contents represent a message to the Company’s directors. The Secretary will forward copies of all correspondence that, in the opinion of the Secretary, deals with the functions of the Board or its committees or that they otherwise determine requires the attention of any member, group or committee of the Board. The Secretary will not forward junk mail, job inquiries, business solicitations, offensive or otherwise inappropriate materials.

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Item 1: Election of Directors

Our bylaws provide for a board of between five and 10 directors, with the exact number fixed from time to time by a resolution of our Board. The Board has fixed the number at seven directors. Each of the nominees is currently a member of our Board of Directors and, other than Mr. Douglas, who joined our Board in September 2024, was elected to our Board of Directors at the 2024 Annual Meeting of Stockholders. Mr. Douglas is standing for election to the Board of Directors for the first time. Mr. Douglas was initially identified as a potential director nominee by our chief executive officer. The NCG Committee then assessed the potential candidacy of Mr. Douglas in light of the director criteria included in our Corporate Governance Policies. Each member of the Board of Directors interviewed Mr. Douglas. Following these interviews, the Board of Directors then met, discussed and approved the appointments of Mr. Douglas to the Board.

Each director elected at the 2025 Annual Meeting will serve until our 2026 Annual Meeting and until their respective successors are duly elected and qualified or until his or her resignation or removal. Each of the nominees has consented to being named in this proxy statement and to continue serving if elected. If any nominee is unable or unwilling to stand for election or serve as a director if elected, the persons named as proxies may vote for a substitute nominee designated by our existing Board of Directors, or our Board may choose to reduce its size.

Vote Required

Our bylaws provide that each director nominee will be elected at the Annual Meeting if they receive a majority of the votes cast with respect to their election in an uncontested election like this one. Consequently, in order to be elected, a nominee must receive more votes “for” than “against” their election. Abstentions and broker non-votes will have no effect on the outcome of the vote.

Under Delaware law, if an incumbent director is not re-elected at a meeting of stockholders at which he or she stands for re-election, then the incumbent director continues to serve in office as a holdover director until his or her successor is elected. To address this “holdover” issue, should any of the nominees fail to receive the vote required to be elected in accordance with our bylaws, that director must promptly tender their resignation to the Board of Directors. In that event, the NCG Committee will make a recommendation to the Board as to whether to accept or reject the tendered resignation or to take another action. The Board will then act on the tendered resignation, taking into account the NCG Committee’s recommendation, and publicly disclose its decision regarding the tendered resignation and the rationale behind the decision within 90 days from the date of the certification of the election results.

In voting for the election of directors, each share has one vote for each position to be filled and there is no cumulative voting.

Recommendation of Board of Directors

Our Board of Directors recommends that you vote FOR each of the director nominees. The persons named as proxies will vote for the election of each of the seven nominees unless you specify otherwise.

2025 Director Nominees

This section provides information on each nominee for the Board of Directors for election at the 2025 Annual Meeting, including their age, Board leadership roles held, and business experience during at least the past five years. We also indicate the name of any other public company for which each nominee currently serves as a director or served as a director during the past five years.

The information on each nominee led our Board to the conclusion that they should serve as a director in light of the Company’s business and structure. We believe that each of these nominees has integrity and adheres to our high ethical standards. In addition, each nominee has demonstrated the ability to exercise sound judgment as well as a commitment to serving the long-term interests of our stockholders.

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Item 1: Election of Directors

Dan L. Batrack		Chairman and CEO	Director since 2005
		Experience • CEO and director since 2005; Chairman since 2008; President from 2008 to 2019 • Joined Tetra Tech in 1980 and has served in numerous capacities, including arctic research scientist, deepwater oceanographic hydrographer, coastal hydrodynamic modeler, environmental data analyst, project and program manager, and President of the Engineering Division, and, in 2004, was appointed Chief Operating Officer • Established the firm’s strategic direction and focus on Leading with Science® to become the premier global consulting firm focused on water, environment, and sustainable infrastructure • Led research and engineering programs in locations in the Arctic and throughout South America, the Middle East, and the United States • Serves as corporate sponsor for several of our clients’ programs and remains engaged in our day-to-day operations
Age	66
		Skills and Qualifications Senior leadership; industry and technical experience; government client regulatory experience; business development and M&A; financial sophistication; innovation/technology; international operations; risk oversight; talent management/compensation. • BA, Business Administration, University of Washington

Gary R. Birkenbeuel		Independent	Director since 2018
		Experience • Retired after 37 years with Ernst & Young LLP (E&Y) • Former Regional Assurance Managing Partner, E&Y, 2003-2017 • Served as the audit partner in charge of multinational publicly and privately held companies engaged in the aerospace and defense, entertainment, technology, and media industries Skills and Qualifications Senior leadership; financial sophistication; audit committee financial expert; certified public accountant; risk oversight; talent management/compensation. • Visiting Professor, Claremont McKenna College • Director and chairman of the investment and audit committees, American Film Institute • BA, Economics, Claremont McKenna College
Age	67
Current Committees:	Chair, Audit; Member, NCG

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John M. Douglas		Independent	Director since 2024
		Experience • CEO and Director of RPS Group Plc, 2017-2023 • CEO and Director of Coffey International Limited, 2011-2016 • CEO of Boral Australian Construction Materials, 2004-2010 Skills and Qualifications Senior leadership; industry and technical expertise; government client regulatory; business development and M&A; financial sophistication; public board; innovation/technology; international operations; risk oversight; talent management/compensation. • Bachelor of Civil Engineering with First Class Honours, Adelaide University • MBA, London Business School
Age	62
Current Committees:	Member, NCG

Prashant Gandhi		Independent	Director since 2022
		Experience • Chief Business Officer of Melio Payments since 2021 • Head of Digital Payments, JP Morgan Chase, 2017-2021 • Partner and Global Chief Operating Officer, Digital Practice, McKinsey & Company, 2000-2016 Skills and Qualifications Senior leadership; business development and M&A; financial sophistication; innovation/technology; international operations; risk oversight; talent management/compensation. • Advisory Board member, University of Minnesota’s School of Information & Decision Sciences • BS, Chemical Engineering, Indian Institute of Technology Delhi • MS, Chemical Engineering, Kansas State University • MBA, University of Chicago’s Booth School of Business
Age	53
Current Committees:	Chair, NCG

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Christiana Obiaya		Independent	Director since 2023
		Experience • CEO and Director of Heliogen since February 2023; CFO 2021-2023 • CFO and Head of Strategy for Bechtel Energy, 2017-2021; leadership roles at Bechtel in finance; strategy; and project development, investment, and execution, 2010-2017 • Prior to Bechtel, worked on renewable energy projects in Kenya and India, 2008-2009; engineer at a multinational consumer goods company, 2004-2008 Skills and Qualifications Senior leadership; industry and technical expertise; government client regulatory; business development and M&A; financial sophistication; public board; innovation/technology; international operations; risk oversight; talent management/ compensation. • BS, Chemical Engineering, Massachusetts Institute of Technology (MIT) • MBA, MIT Sloan School of Management
Age	42
Current Committees:	Member, Compensation
Other Current Public Boards:	Heliogen, Inc.

Kimberly E. Ritrievi		Independent	Director since 2013
		Experience • President of The Ritrievi Group LLC, since 2005 • Advisor to technology and chemical companies on financial strategies, 2005-2018; private investor 2018-present • Codirector, Americas Investment Research, Goldman, Sachs & Co., 2001-2004; Specialty Chemical Analyst, Goldman, Sachs & Co., Credit Suisse First Boston, Lehman Brothers, and Paine Webber Skills and Qualifications Senior leadership; business development and M&A; industry and technical expertise; financial sophistication; audit committee financial expert; international operations; public board; innovation/technology; risk oversight; talent management. Designated ESG expert and National Association of Corporate Directors certified director. • Princeton University School of Engineering and Applied Science Leadership Council; Massachusetts Institute of Technology (MIT) Sandbox Funding Board; Wellesley Centers for Women Council of Advisors • Chair of the Board, Mativ Holding, Inc. • Advisory Director, Intrinio • BS, Chemical Engineering, Princeton University • MS, Management, MIT Sloan School of Management • ScD, Chemical Engineering, MIT
Age	66
Current Committees:	Member, Audit; Member, Compensation
Other Current Public Boards:	Mativ Holdings, Inc.

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Kirsten M. Volpi		Independent, Presiding Director	Director since 2013
		Experience • EVP, COO, and CFO, Colorado School of Mines, since 2013; Senior Vice President for Finance and Administration, CFO, and Treasurer, 2005-2011 • Chief Administrative Officer, U.S. Olympic Committee, 2011-2013 • Various financial management roles for Rensselaer Polytechnic Institute, University of Colorado Foundation, and American Water Works Association Skills and Qualifications Senior leadership; financial sophistication; audit committee financial expert; certified public accountant; international operations; risk oversight; talent management/compensation. • BS, Accounting, University of Colorado
Age	60
Current Committees:	Member, Audit; Chair, Compensation

Chairman Emeritus

Dr. Li-San Hwang has served as our honorary Chairman Emeritus since March 2006. As Chairman Emeritus, Dr. Hwang is invited to attend Board and Board committee meetings, but he does not have voting rights. Chairman Emeritus is an unpaid position. Dr. Hwang joined our predecessor in 1967 and led our acquisition of the Water Management Group of Tetra Tech from Honeywell Inc. in March 1988. He served as our CEO from our formation until November 2005. Dr. Hwang has served as an advisor to numerous government and professional society committees and has published extensively in the field of hydrodynamics. He is a graduate of the National Taiwan University, Michigan State University, and California Institute of Technology, holding BS, MS, and PhD degrees, respectively, in civil engineering, specializing in water resources.

Director Compensation

The Compensation Committee works with the independent compensation consultant, Meridian Compensation Partners, LLC (Meridian), to target nonemployee director compensation within a competitive range of the median of our peer companies to support the recruitment and retention of our nonemployee directors. The majority of each director’s compensation is delivered in equity to align director interests with those of our stockholders. Under our stock ownership guidelines, each nonemployee director must own shares having a value equal to at least five times the nonemployee director’s annual base cash retainer. Directors have five years from the date of their election to the Board to attain the required level of stock ownership.

FY 2024 Cash Compensation

During FY 2024, our nonemployee director cash compensation program consisted of the following elements.

	Annual Nonemployee Director Cash Compensation
	Cash retainer				$110,000
	Additional cash retainer for Presiding Director				$35,000
	Additional cash retainer for Audit Committee Chair				$20,000
	Additional cash retainer for Compensation Committee Chair				$18,000
	Additional cash retainer for NCG Committee Chair				$15,000
	Additional cash retainer for Audit Committee and Compensation Committee membership				$5,000
	Additional fee per in-person or telephonic Board or committee meetings in excess of eight				$2,000

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FY 2024 Equity Compensation

During FY 2024, our nonemployee director equity compensation program consisted of an equity award based on a fixed dollar value of $175,000. The following table describes the awards granted on November 21, 2023.

PSU and RSU Awards Granted

Type of Award	Shares Underlying Award (#)	Description
Performance Stock Units (PSUs)	3,190	Represents target shares underlying the award. PSUs have a three-year performance period with cliff vesting on the applicable vesting date and with the same terms as the PSUs awarded to our executive officers, subject to the achievement of the applicable performance goals. PSUs vest immediately upon change in control or upon departure from the Board after serving 10 years or more, having served the full term for which the director was elected, and subject to achievement of the applicable performance criteria. Upon the director’s departure having served less than 10 years or upon death or disability, PSUs vest on a pro rata basis on the scheduled vesting date and subject to achievement of the applicable performance criteria. For additional information concerning PSU vesting, refer to the Compensation Discussion and Analysis section on page 39 of this proxy statement.
Restricted Stock Units (RSUs)	2,125	Vested on November 30, 2024, if the director had not ceased to be a director prior to that date. RSUs vest immediately upon change in control or upon departure from the Board after serving 10 years or more and having served the full term for which the director was elected. Upon the director’s departure having served less than 10 years, RSUs vest on a pro rata basis. Upon the director’s death or disability, unvested RSUs are forfeited.

Director Compensation Table

The following table provides information concerning the compensation for services of our nonemployee directors during FY 2024.

Direct Compensation by Director

Name1	Fees Earned or Paid in Cash ($)	Option Awards ($)2	Stock Awards ($)3	Total ($)
Mr. Birkenbeuel	130,000	0	199,695	329,695
Mr. Gandhi	110,000	0	199,695	309,695
Ms. Maguire4	165,000	0	199,695	364,695
Ms. Obiaya	115,000	0	199,695	314,695
Dr. Ritrievi	130,000	0	199,695	329,695
Ms. Volpi	154,599	0	199,695	354,654

1 Mr. Batrack does not appear in the table because he received compensation as our CEO and does not receive any additional compensation as director. Mr. Douglas does not appear in the table because he joined the Board on September 30, 2024 following the completion of FY 2024.

2 No stock options were granted to nonemployee directors in FY 2024. For information regarding the number of stock options held by each nonemployee director as of September 29, 2024, see the Stock Options Outstanding (#) column in the Nonqualified Stock Options, Unvested PSUs, and Unvested RSUs by Director table below.

3 $129,859 of the amounts in the Stock Awards column represent the aggregate grant date fair values, without adjustment for forfeitures, of PSUs that are payable at the end of a three-year performance period provided that the performance objectives are achieved as of the end of the period. The actual number of shares issued can range from 0% to 200% of the target shares at the time of grant. The performance objectives that determine the number of shares that may be earned for the PSUs were (i) as to 50% of the award, growth in earnings per share, which is a performance condition under FASB ASC Topic 718, and (ii) as to 50% of the award, total stockholder return (TSR), which is a market condition under FASB ASC Topic 718, relative to the TSR of (A) 16 companies objectively determined based on GICS code and revenue size (25% of award) and (B) the S&P 1000 (25% of award), in each case computed over the three-year performance period. The performance condition component of the fair value of PSUs was determined based on the fair market value of our common stock on the date of grant. The market condition component of the fair value of the PSUs was determined as of the date of grant using the Monte Carlo simulation method, which uses multiple input variables to estimate the probability of meeting the performance objectives established for the award, including the expected volatility of our stock price and other assumptions appropriate for determining fair value. Based on these computations, the grant date fair values of the performance condition-based PSU awards and the market condition-based PSU awards granted on November 21,2023, to each nonemployee director on that date were $32.86 and $48.55 per share, respectively. The maximum grant date fair value of the PSU awards in FY 2024 (200% vesting) was $259,717 for each of the nonemployee

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Item 1: Election of Directors

directors. There can be no assurance that these grant date fair values will be realized by the nonemployee directors. For information regarding the number of unvested PSUs held by each nonemployee director as of September 29, 2024, see the Unvested PSUs Outstanding column in the table below. $69,836 of the amounts in the Stock Awards column represent the aggregate grant date fair values, computed in accordance with FASB ASC Topic 718, of RSU awards. The grant date fair value of these awards is calculated using the closing price of our common stock on the grant date as if these awards were vested and issued on the grant date. The grant date fair value of the RSU awards granted on November 21,2023, to each nonemployee director was $32.86 per share. There can be no assurance that these grant date fair values will ever be realized by the nonemployee directors. For information regarding the number of unvested RSUs held by each nonemployee director as of September 29, 2024, see the Unvested RSUs Outstanding column in the Nonqualified Stock Options, Unvested PSUs, and Unvested RSUs by Director table below.

4 Ms. Maguire resigned from the Board on September 30, 2024. Mr. Douglas joined the Board on September 30, 2024 and accordingly did not receive any compensation for service during FY24 and has not been included in the table above.

Each of the nonemployee directors listed below owned the following number of nonqualified stock options, unvested PSUs, and unvested RSUs as of September 29, 2024.

Nonqualified Stock Options, Unvested PSUs, and Unvested RSUs by Director

Name	Stock Options Outstanding (#)	Unvested PSUs Outstanding (#)	Unvested RSUs Outstanding (#)
Mr. Birkenbeuel	0	8,430	2,125
Mr. Gandhi	0	8,715	2,125
Ms. Maguire	62,000	8,430	2,125
Ms. Obiaya	0	5,720	2,125
Dr. Ritrievi	0	8,430	2,125
Ms. Volpi	16,000	8,430	2,125

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Item 2: Advisory Vote to Approve Our Named Executive Officers’ Compensation

Our Board has determined to hold annual “say on pay” votes, which ask stockholders to vote on the compensation of our named executive officers (NEOs). Our stockholders are being asked to vote on the following resolution:

RESOLVED, that our stockholders approve, on an advisory basis, the compensation of our Named Executive Officers, as described in the Compensation Discussion and Analysis and Executive Compensation Tables sections of our 2025 proxy statement.

Vote Required

Approval of this advisory vote requires the affirmative vote of a majority of shares of common stock present or represented and entitled to vote on the proposal at the 2025 Annual Meeting. Abstentions will have the same effect as a vote “AGAINST” the proposal. Broker non-votes will have no effect on the outcome of the advisory vote.

Recommendation of Board of Directors

The Compensation Committee considered feedback from stockholders regarding our executive compensation program and has previously made significant changes to the program to both address suggestions made by our stockholders and more closely align our compensation program with our current financial position and business strategies. Our Board of Directors recommends that you vote FOR approval, on an advisory basis, of our named executive officers’ compensation. Properly dated and signed proxies will be so voted unless stockholders specify otherwise.

Meaning of Advisory Vote

The advisory vote is a vote to approve the compensation of our NEOs, as described in the Compensation Discussion and Analysis section on page 39 and Executive Compensation Tables section on page 60 of this proxy statement. It is not a vote on our general compensation policies or any specific element thereof, the compensation of our nonemployee directors, or our program features designed to prevent excessive risk taking as described in Risks Associated with Compensation Policies and Practices section on page 25 of this proxy statement.

The results of the advisory vote are not binding on our Board. In accordance with SEC regulations, however, the Compensation Committee will disclose the extent to which it takes into account the results of the vote in the Compensation Discussion and Analysis section of our 2026 proxy statement. We remain committed to continued engagement with our stockholders to solicit and consider their viewpoints and discuss why we believe our executive compensation program properly aligns with our strategies and incents our executives to achieve strong, long-term operating and financial performance for our stockholders.

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Compensation Discussion and Analysis

This compensation discussion and analysis (CD&A) provides an overview of the principles and practices underlying our executive compensation program and the decisions made by the Compensation Committee related to FY 2024 compensation for our Named Executive Officers.

This CD&A and the Executive Compensation Tables section on page 60 of this proxy statement provide compensation information for our NEOs for FY 2024, who are identified in the table below.

FY 2024 Named Executive Officers

Name	Title	Years in Position at FYE 20241	Years at Tetra Tech at FYE 2024
Dan L. Batrack	Chairman, CEO	19	44
Steven M. Burdick	EVP, CFO	13	21
Leslie L. Shoemaker	EVP, Chief Innovation and Sustainability Officer	2	33
Preston Hopson	SVP, General Counsel, and Secretary	7	7
Roger R. Argus	SVP and President, Government Services Group (GSG) and Commercial/International Group (CIG)	7	31

1 FYE 2024 was September 29, 2024.

FY 2024 Performance Summary

Tetra Tech’s FY 2024 operating results were strong and demonstrated increased performance compared to FY 2023, which was itself a year of strong operational and financial performance. In FY 2024 we achieved record annual results for revenue, operating income, earnings, adjusted EBITDA, and cash flow. Our focus on providing clients with high-end differentiated consulting and engineering services has resulted in increased margins and reduced risk in our business.

We ended FY 2024 with an authorized and funded backlog that reached another all-time high of approximately $5.4 billion.

Highlights of our FY 2024 results of operations as reported in our FY 2024 Annual Report on Form 10-K are noted in the table below.

FY 2024 Highlights
($ in millions, except EPS and percentages)

	$	vs. FY 2023
Revenue	$5,199	+15%
Operating Income	$501	+40%
EPS	$1.23	+21%
Backlog	$5,376	+12%

Disciplined Capital Allocation

We achieved these results while maintaining a healthy balance sheet and continuing the disciplined execution of our capital allocation strategy. Over the last three years, we have returned $357 million to our stockholders through dividends and stock repurchases. In FY 2024, we returned $59 million to our stockholders by paying an aggregate dividend of $0.22 per share on a post-split basis. The Company effected a five-for-one forward stock split at 5:00 p.m. Eastern Time on September 6, 2024. We have paid quarterly dividends since April 2014 and increased our dividend from $.01 at inception to $0.06 per share in December 2024, a 300% increase over this period.

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Compensation Discussion and Analysis

Strong Stock Price Performance

Our one-year TSR was 53% and our cumulative three-year TSR was 55%. TSR measures the return we have provided our stockholders, including stock price appreciation and dividends paid (assuming reinvestment thereof). We compare our TSR to the S&P 1000 and our TSR peer group (listed on page 53 of this proxy statement) for purposes of our LTI program, as more fully explained below. We outperformed these market comparisons over both the one-year period and three-year period.

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Compensation Discussion and Analysis

Strong Compensation Governance Practices

Our executive compensation program incorporates what we believe are best practices, as shown in the following table, which we believe ensure that the program serves the long-term interests of our stockholders.

	Policy or Best Practice				Description and Benefit to Our Stockholders
	Majority of Compensation Performance-Based				For FY 2024, 88% of our CEO’s target total direct compensation (TDC) (base salary + annual cash incentive opportunity + long-term equity incentive opportunity) and an average of 72% of our NEOs’ target TDC was at-risk (all compensation components other than base salary).
	Median Targeting				TDC and the components thereof are generally targeted to be within a competitive range of the median of companies similar in size, scope, and complexity, with variability based on various consideration such as responsibilities, individual performance, tenure, retention, succession, and market factors. Pay decisions are not formulaic and the Committee uses its judgement and consideration of various factors such as individual performance, succession planning, and industry expertise to further determine appropriate pay levels and market positioning.
	Capped Annual Incentive				Annual cash incentive compensation is based primarily on our achievement of performance objectives in the categories of revenue, operating income, cash flow from operating activities, and backlog, with consideration for individual performance, with awards ranging from 0% to a cap of 200% of target.
	Majority Long-Term Equity Incentive Compensation				The majority of our equity-based incentive awards emphasize our long-term performance, with PSUs cliff vesting at the end of three years, subject to achievement of the applicable performance goals. Equity compensation aligns NEO interests with stockholder interests by delivering compensation dependent on our long-term performance and stockholder value creation.
	Rigorous Goal Setting Process				Annual review and approval are completed by the Compensation Committee of the performance goals for the Company (Corporate) and for our business groups. The performance factor used to determine AIP awards is increased or decreased based upon the growth level of the targets from the prior fiscal year.
	No Employment Agreements				Our NEOs are employed at will, and they have no special severance benefits in the absence of a change in control.
	Stock Ownership Guidelines				Our NEOs are required to obtain and maintain shares having a value equal to at least 2x to 6x base salary (based on position). All our NEOs are in compliance with our stock ownership guidelines.
	No Hedging or Pledging				Our insider trading policy prohibits our directors and officers from hedging or pledging our common stock, and all our NEOs are in compliance with that policy.
	Clawback Policy				Our clawback policy provides that in the event we are required to prepare an accounting restatement, we will recover, in accordance with the terms of the policy, compensation received after its effective date by any current or former executive officer that is based wholly or in part upon the attainment of a financial reporting measure.
	No Excise Tax Gross Ups				We do not provide excise tax gross up payments in connection with a change in control.
	Double Trigger Equity Vesting				No equity awards will be accelerated in connection with a change in control unless the NEO’s employment is terminated without cause or the NEO terminates employment for good reason within two years thereof.
	No Repricing/Exchange of Underwater Stock Options				Our Equity Incentive Plan prohibits the repricing/exchange of underwater options without stockholder approval.
	Limited Perquisites				Our NEOs receive limited capped reimbursements for vehicle use, financial planning, tax planning, memberships, and annual physical examinations. These reimbursements are not subject to any tax gross up.
	Independent Oversight				The Compensation Committee is comprised solely of independent directors.
	Independent Expert Advice				Meridian, which has been determined by the Compensation Committee to be independent and free of conflicts of interest, provides the Committee with expert executive compensation advice. Meridian has served as the independent advisor since January 2016.

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Compensation Discussion and Analysis

2024 Say on Pay Vote and Executive Compensation Program

At the 2024 Annual Meeting, approximately 93% of votes cast approved our FY 2023 executive compensation program. It is our practice to take stockholder feedback into consideration as we discuss and implement compensation design changes. During FY 2024, the Compensation Committee reviewed best practices for executive compensation and evaluated the vote results at the 2024 Annual Meeting and the results of our ongoing stockholder outreach program. Telephone conferences with our investors were attended by members of management in our legal, investor relations, and executive compensation functions. The feedback was subsequently reported to the Compensation Committee, and the Compensation Committee was able to develop a clear understanding of stockholder views. The Compensation Committee remains committed to the ongoing evaluation of our executive compensation program and adjustments to this program to reflect feedback received from stockholders.

Stockholder Engagement

Our ongoing engagement program begins in February of each year, following the filing of our proxy statement in January. After we file our proxy statement with the SEC, we reach out to our largest investors (generally representing 50% to 70% of our shares outstanding as of the record date), sharing these materials and offering a conversation to discuss our executive compensation and answer questions. On the day of the Annual Meeting, we discuss preliminary vote results with our Board and follow up with Board committees in the spring with a more detailed analysis of actual results, including feedback from investors and views of proxy advisory firms. In the fall, we again reach out to our largest investors to discuss executive compensation to hear what issues are important to our stockholders. In the winter, we review the feedback from our fall outreach effort with management and our Board and consider whether any changes to our executive compensation program are advisable. We also keep investor feedback in mind as we prepare our next proxy statement by enhancing or clarifying our disclosure as appropriate.

Following the 2024 say on pay vote, as part of our stockholder outreach program, we proactively contacted our largest institutional stockholders, representing approximately 60% of our outstanding shares as of the record date for the 2024 Annual Meeting, to solicit their views on our executive compensation program and make directors and management available to answer questions and address concerns. Additionally, our senior management team, including our CEO and CFO, regularly engage in meaningful dialogue with our stockholders through our quarterly earnings calls and other channels of communication.

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Compensation Discussion and Analysis

Pay Philosophy and Executive Compensation Components

We believe in a pay for performance compensation program in which a majority of the compensation is tied to our success in meeting predetermined performance objectives and creating long-term stockholder value. The objective of this strategy is to motivate our executives to achieve our annual and long-term financial goals, align with stockholders, and recognize the executives’ contributions in delivering strong corporate and/or business group performance. The Compensation Committee implements this philosophy and provides incentives to our executives by following three key principles:

•

Positioning target total direct compensation (TDC) and each component thereof at approximately market median with additional consideration given to various factors as discussed previously. An NEO’s pay positioning is not formulaic; failure to achieve financial objectives and create stockholder value should directly impact TDC relative to market median compensation

•

Aligning our annual incentive awards with our AOP and key financial and strategic objectives, which are predetermined and objectively measurable

•

Rewarding long-term performance using metrics such as EPS growth and relative TSR, which focuses executives on consistent and sustainable stockholder value creation

The Compensation Committee references 25th percentile, median and 75th percentile TDC and compensation components of companies similar in size, scope, and complexity with which we compete for executive talent, and then further considers responsibilities, individual performance, tenure, retention, company performance, succession planning, and market factors for each executive to make final pay decisions. The Committee believes this varied positioning and approach is appropriate given our business portfolio mix, the diversity of our services, and the global nature of our operations, which require our executives to have a wide range of business leadership experience and skills.

Our incentive compensation for FY 2024 consisted of the AIP and LTI awards. The AIP award payouts were based on our performance against performance goals established by the Compensation Committee in November 2023 for revenue, operating income, cash flow, and backlog. The AIP rewards NEOs based on corporate and/or business group and/or division performance as well as individual contributions to motivate the NEOs and align their compensation with stockholder interests. Both our AIP and our PSU awards under our LTI program provide upside opportunity for exceeding performance targets and downside risk, including forfeiture of PSUs and no payout under our AIP for failing to achieve predetermined performance targets. Our compensation is aligned with performance, and our ability to exceed or failure to achieve our performance targets directly impacts payments to our NEOs and their compensation relative to the market median. The following graphic illustrates the components of our executive compensation program.

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Compensation Discussion and Analysis

Components of Annual and Long-Term Compensation

In FY 2024, as shown in the following graphic, 88% of our CEO’s target TDC and an average of 72% of our other NEOs’ target TDC was at risk (all compensation components other than base salary).

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Compensation Discussion and Analysis

FY 2024 NEO Target TDC Mix

Summary of Compensation Decisions for FY 2024

The key elements of our FY 2024 NEO target TDC are shown in the following table. While we provide consistent, market competitive TDC opportunities for our NEOs, the actual compensation they realize varies year to year based on our performance.

Our CEO is not involved in the decisions regarding his own compensation, which is determined by the Compensation Committee in an executive session with consultation from Meridian.

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Compensation Discussion and Analysis

FY 2024 NEO TDC

Component	Purpose	Decisions Impacting FY 2024 Executive Compensation
Fixed
Base Salary	Provides fixed, market- competitive monthly income for performing daily responsibilities	• The Committee increased the CEO’s base salary by 2% in FY 2024 to reflect prior year performance, tenure, and overall market competitive base pay • The Committee adjusted the other NEO base salaries to reflect prior year performance or position their salaries at or around the market median, with increases ranging from approximately 2% to 8%
Performance-Based Cash
AIP Award	Provides variable, cash-based incentive to motivate our executives annually to grow revenue, increase profitability, deliver strong cash flow, and replenish backlog consistent with our AOP financial objectives	• Target bonus opportunity, as a percentage of base salary, was 150% for the CEO, 100% for the CFO, 80% for other EVPs, and 85% for the general counsel and the SVPs with group president roles • The corporate and business group performance factor has a range of 0 to 2.0, with a target of 1.0 based on achievement of four AOP targets (revenue, operating income, cash flow, and backlog) • The Committee may make limited adjustments to AIP payments based on individual performance and contributions • Minimum (threshold), target, and maximum performance criteria and payouts were established for each metric, with payout at 0% of target below threshold performance, 50% of target at threshold, 100% of target at target, and 200% of target at maximum. The individual performance modifier may range from +/-20%
Long-Term Incentives
PSUs and RSUs	Provide variable equity-based incentive compensation to enhance the alignment of our executives’ interests with stockholder interests and drive long-term value creation Provide LTI opportunity, including vehicle selections, performance criteria and weightings based on market data, our pay philosophy, and independent consultant recommendations	• For FY 2024, the value of the target LTI opportunities for the CEO, CFO and SVPs were adjusted to target the market median while also considering internal equity, retention, and individual performance and role, among other factors • PSUs have a three-year performance period with cliff vesting, subject to achievement of the applicable performance goals; vesting is determined 50% by EPS growth and 50% by relative TSR: ◦ EPS based vesting ranges from 0% for less than 2% average annual EPS growth to 200% for greater than or equal to 16% average annual EPS growth ◦ TSR based vesting ranges from 0% if our TSR is less than the 25th percentile of the TSR peer groups to 200% if our TSR is at the 75th or higher percentile of the TSR peer groups • RSUs have time-based vesting at the rate of 25% per year, subject to the holder’s continuous employment by us through the applicable vesting date

In addition to these primary elements of our executive compensation program, we also provide our NEOs with limited perquisites and benefits, as specified in the Strong Compensation Governance Practices section on page 40 of this proxy statement.

Assessment of Pay for Performance

Our Compensation Committee designed the executive compensation program to reflect its philosophy that a majority of compensation should be tied to our success in meeting predetermined performance objectives, the achievement of which should positively influence our stock price. The objective is to motivate the executives to achieve these annual and long-term financial goals in order to deliver consistent and sustainable return to our stockholders.

Discussion of Compensation Components and Decisions Impacting FY 2024 Compensation

The Compensation Committee targets base salaries at or around the market median, with the majority of NEO compensation consisting of incentive compensation to advance the Committee’s pay for performance philosophy. This methodology drives higher realized compensation when our financial performance is stronger and lower realized compensation when our financial performance is weaker. It provides the Committee with the flexibility to respond to changing business conditions, manage compensation in accordance with career progression, and adjust compensation to reflect differences in executive experience and performance.

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Compensation Discussion and Analysis

FY 2024 Base Salary

In November 2023, the Compensation Committee approved the base salary adjustments shown in the following table for our NEOs, and the adjustments were not retroactive to the beginning of FY 2024. Accordingly, the base salary amounts do not necessarily conform to the amounts contained in the Summary Compensation Table on page 60 of this proxy statement, which reflect the salary actually earned during FY 2024. Increases are generally driven by prior year performance, tenure, and overall market median for positions with similar scope and responsibility.

FY 2024 NEO Base Salaries

Name	FY 2023 Base Salary ($)	% Increase	FY 2024 Base Salary ($)
Mr. Batrack	1,200,000	2.1	1,225,000
Mr. Burdick	625,000	8.0	675,000
Dr. Shoemaker	585,000	2.6	600,000
Mr. Hopson	510,000	7.8	550,000
Mr. Argus	510,000	7.8	550,000

FY 2024 AIP Award Program

The Compensation Committee grants AIP awards under our Executive Compensation Plan approved by our stockholders in 2014. No amounts are paid under the Executive Compensation Plan unless we have positive net income (as defined under the Plan). The AIP awards are used to motivate NEOs to meet and exceed annual company objectives. These incentives are paid to reward the achievement of specified operating, financial, strategic, and individual measures and goals that are expected to contribute to stockholder value creation.

AIP Performance Measures and Targets

The AIP uses four financial metrics when the Committee is determining payments under the Executive Compensation Plan. Each November, a target level is established for each of the four financial metrics based on the AOP for the business groups, as well as the Company as a whole. In setting the targets, the Board and Compensation Committee aim to align our long-term financial goals and the drivers of our long-term stockholder value.

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Compensation Discussion and Analysis

The four financial metrics, including rationale for their inclusion in the AIP and the results of the FY 2024 AIP, are illustrated in the table below.

AIP Award Program Financial Metrics

Metric

FY 2024
Weighting

What it Measures and
How It Aligns

Threshold/
Maximum
as a % of
Target

FY 2024
Target1
($ in
thousands)

FY 2024
Actual2
($ in
thousands)

FY 2023
Actual2
($ in
thousands)

Revenue

20%

Measures the growth of our business and is a leading driver of stockholder value creation.

Aligns with our growth and durable competitive advantage drivers.

85% / 115%

Corporate:
$4,975,000

GSG:
$2,239,000

CIG:
$2,736,000

Corporate:
$5,198,724

GSG:
$2,439,636

CIG:
$2,786,775

Corporate:
$4,522,550

GSG:
$2,159,000

CIG:
$2,425,000

Operating Income

40%

Primary measure used by stockholders and analysts to evaluate our profitability.

Aligns with our margin, durable competitive advantage, and ERM drivers.

75% / 125%

Corporate:
$470,000

GSG:
$234,000

CIG:
$304,000

Corporate:
$510,498

GSG:
$274,649

CIG:
$328,509

Corporate:
$419,921

GSG:
$238,553

CIG:
$252,052

Cash Flow

20%

Demonstrates our ability to collect on receivables billed to clients and allows us to invest in our business and return funds to stockholders through dividends and share repurchases.

Aligns with our capital allocation driver.

75% / 125%

Corporate:
$300,000

GSG:
$210,000

CIG:
$337,000

Corporate:
$358,724

GSG:
$265,218

CIG:
$352,875

Corporate:
$405,421

GSG:
$287.552

CIG:
$255,821

Backlog

20%

Positions us for growth going forward based upon authorized and funded projects.

Aligns with our growth and durable competitive advantage drivers.

85% / 115%

Corporate:
$5,030,000

GSG:
$2,698,000

CIG:
$2,282,000

Corporate:
$5,376,056

GSG:
$3,161,656

CIG:
$2,238,291

Corporate:
$4,790,442

GSG:
$2,713,000

CIG:
$2,123,000

1 Corporate AOP is based on business group AOPs, augmented by planned acquisitions, that are aligned with our business and stockholder interests. The AOPs for business groups include no acquisitions, since capital allocation strategy is implemented at Corporate.

2 With respect to Corporate, results exclude the impact of acquisition related charges, non-core disposition related charges, and one-time, non-recurring tax adjustments in FY 2024. With respect to the business groups, results include only 50% of the impact of acquisitions in FY 2024. This inclusion reflects the business group presidents’ responsibility to oversee the performance of and successfully integrate acquisitions.

The AIP awards for our NEOs are based on the level of achievement of performance of the business for which they were responsible. The chart below indicates respective weightings for business performance for each NEO.

[MISSING IMAGE: tbl_awardbusiness-pn.jpg]

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Compensation Discussion and Analysis

Minimum (threshold), target, and maximum performance criteria and payouts were established for each metric as indicated above. Payout percentages are reflected in the table below with straight line interpolation for performance between threshold and target and between target and maximum. No bonus is earned with respect to a metric if performance is below threshold, and no additional bonus is earned for performance above maximum.

Payout Percentages

Further, a financial modifier or “growth factor,” is applied to adjust the payout, either upward or downward, based on whether the AOP target is aggressive or conservative as compared to the prior year. This growth factor assists in validating the rigor of our AOP goals. Additional details on both the financial and individual performance elements of our AIP are provided below.

AIP Award Formula

NEO AIP awards are determined using the following formula.

Corporate Performance Factor Range

The Corporate Performance Factor (CPF) has a range of 0 to 2.0 with a target of 1.0 based on achievement of the AOP performance targets established in the AOP. Specifically, for each of the four metrics, the Compensation Committee reviewed FY 2024 performance as a percentage of the target and determined an award percentage. The results were then averaged to determine the preliminary CPF.

Growth Factor

The Compensation Committee believes in setting aggressive targets. Accordingly, the preliminary CPF was increased or decreased based upon the growth level of the AOP targets from the prior fiscal year. That approach rewards demanding targets and penalizes targets established with smaller increases relative to the prior year. The growth factors indicated below were applied to each metric and the results were averaged to determine the final CPF.

FY 2024 CPF Modifiers

The following tables show the AIP financial modifiers for our NEOs for FY 2024. Our performance resulted in modifiers of 1.4903 for Mr. Batrack, Mr. Burdick, Dr. Shoemaker, and Mr. Hopson based on Corporate results and 1.4860 for Mr. Argus based on Government Services Group (GSG) and Commercial/International Group (CIG) results, weighted 50% for GSG results and 50% for CIG results. The weighting of the revenue, operating income, cash flow, and backlog factors was 20%, 40%, 20%, and 20%, respectively.

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Compensation Discussion and Analysis

Corporate Performance
($ in thousands)

Objective	Actual FY 2023	Actual FY 2024	Target FY 2024	Actual FY 2024 as a % of Target FY 2024	Preliminary CPF (0-2.0)	Growth % / Growth Factor	Weight	Final CPF (0-2.0)
Revenue	4,522,550	5,198,724	4,975,000	104.50	1.300	10/1.1	0.2	1.430
Operating Income	419,921	510,498	470,000	108.62	1.345	12/1.1	0.4	1.479
Cash Flow	405,321	358,724	300,000	119.57	1.783	-26/0.9	0.2	1.605
Backlog	4,790,442	5,376,056	5,030,000	106.88	1.459	5/1.0	0.2	1.459
CPF					1.446			1.4903

GSG Performance
($ in thousands)

Objective	Actual FY 2023	Actual FY 20241	Target FY 2024	Actual FY 2024 as a % of Target FY 2024	Preliminary CPF (0-2.0)	Growth % / Growth Factor	Weight	Final CPF (0-2.0)
Revenue	2,159,000	2,439,636	2,239,000	108.96	1.597	4/0.9	0.2	1.438
Operating Income	238,553	274,650	234,000	117.37	1.695	-2/0.9	0.4	1.525
Cash Flow	287,552	265,218	210,000	126.29	2.000	-27/0.9	0.2	1.800
Backlog	2,713,000	3,161,657	2,698,000	117.19	2.000	-1/0.9	0.2	1.800
CPF					1.797			1.618

1 Reflects 50% of the impact of acquisitions

CIG Performance
($ in thousands)

Objective	Actual FY 2023	Actual FY 20241	Target FY 2024	Actual FY 2024 as a % of Target FY 2024	Preliminary CPF (0-2.0)	Growth % / Growth Factor	Weight	Final CPF (0-2.0)
Revenue	2,425,000	2,786,775	2,736,000	101.86	1.124	13/1.1	0.2	1.236
Operating Income	252,052	328,509	304,000	108.06	1.322	21/1.2	0.4	1.587
Cash Flow	255,821	352,875	337,000	104.71	1.188	32/1.2	0.2	1.426
Backlog	2,123,000	2,238,291	2,282,000	98.08	0.936	7/1.0	0.2	0.936
CPF					1.179			1.354

1 Reflects 50% of the impact of acquisitions.

FY 2024 NEO Performance Evaluations

The Compensation Committee may adjust each NEO’s compensation under the Executive Compensation Plan based upon the NEO’s individual performance. For adjustments to the CFO’s compensation based on individual performance, the Audit Committee and Compensation Committee would jointly approve them.

Adjustments would be based on an assessment of the NEO’s performance, including contributions to the successful achievement of annual operating goals, leadership in the NEO’s area of responsibility, strategic planning, and implementation of applicable corporate objectives.

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Compensation Discussion and Analysis

In FY 2024, the operational objectives were as follows:

•

Advancing our culture of diversity, equity, and inclusion

•

Advancing our ESG programs

•

Maintaining high standards in business ethics

•

Maintaining high standards in customer service

•

Enhancing our organizational structure

•

Providing a safe and healthy workplace for employees

•

Developing a three-year strategic plan that achieves value creation objectives

•

Further implementing the contract management process to minimize risk and surprises, which aligns with our ERM driver

•

Improving key management metrics and reporting

•

Improving corporate wide marketing functions and processes

•

Winning key/targeted program competitions, which aligns with our growth driver

•

Further implementing our enterprise resource planning system migration plan

•

Identifying succession candidates for all executive positions

•

Targeting corporate general and administrative expenses not to exceed a specified percentage of revenue

•

Reducing legal and risk management insurance expenses while maintaining service levels

For FY 2024, the Compensation Committee considered the individual performance of each of the NEOs and approved a 20% upward modification to the AIP awards of Mr. Batrack, Mr. Burdick, Dr. Shoemaker, and Mr. Hopson, all in recognition of their extraordinary contributions during an unprecedented fiscal year. For Mr. Burdick, the approval was provided jointly by the Compensation Committee and the Audit Committee. The basis for the Compensation Committee’s decisions, including these modifications, is described below.

Mr. Batrack continued to successfully implement our ongoing Strategic Plan, tied to key drivers to create stockholder value. As a result of his leadership and strategy execution, Tetra Tech achieved historic performance in FY 2024, reaching all-time record highs in revenue, net revenue, operating income, earnings and backlog. In addition, he spearheaded Tetra Tech’s inaugural investor day event, establishing our 2030 vision and metrics, and completed a 5-for-1 forward stock split with record stock performance. Notably, he facilitated the sustained growth of our high-margin, highly differentiated operations. In furtherance of our digital strategy, Mr. Batrack supported the continued growth of Tetra Tech’s software subscription practice. Furthermore, Mr. Batrack oversaw the successful integration of RPS Group as well as the acquisition and integration of LS Technologies. He also continued to develop, train, and retain a strong and qualified executive team with a focus on succession planning throughout the Company, resulting in the promotions of diverse and internal candidates to key operational leadership positions.

Mr. Burdick contributed to Tetra Tech’s successful FY 2024 through strong financial management across the global operations. He was instrumental to the success of the RPS Group integration process and transition to Tetra Tech’s enterprise resource planning system. Importantly, he developed and implemented an enhanced capital allocation strategy to optimize Tetra Tech’s capital structure and to successfully reduce the Company’s leverage. Mr. Burdick also significantly contributed to the planning for Tetra Tech’s inaugural investor day event. He oversaw the 5-for-1 forward stock split process from inception to completion. Mr. Burdick provided leadership on the identification, due diligence, closure, and financial integration of multiple EPS accretive strategic acquisition targets. In addition, he continued to oversee our credit facility, has maintained advantageous rates to the benefit of Tetra Tech, and facilitated achievement of sustainability goals in our credit facility, resulting in substantial interest savings to the Company.

Dr. Shoemaker led our innovation and sustainability efforts. As our chief sustainability officer, she executed on the plan to achieve our 2025 interim targets, and 2030 sustainability goals outlined in our comprehensive sustainability report. She enhanced our sustainability reporting process, resulting in increased rating agency sustainability ratings. In addition, Dr. Shoemaker oversaw innovation across the Company, inculcating it in our operations across the Company and resulting in tangible successes with our clients. She personally spearheaded our new software subscription practice, developing a strategy for recurring revenue for the Company. She continued to oversee our Leadership Academy to effectively identify, develop, and promote a diverse group of employees with potential to rise to senior leadership roles. Dr. Shoemaker also led our company-wide strategic digital hiring initiative and served as executive sponsor for the emerging professionals employee resource group.

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Mr. Hopson advised our Board of Directors and executive leadership on corporate governance and social responsibility issues. He oversaw the resolution of significant litigation matters and supported finance initiatives, including the 5-for-1 forward stock split process and our inaugural investor day event. He closed several acquisitions and championed the legal, compliance and human resources integration processes for RPS Group. Mr. Hopson also supported the Board of Directors in its executive and director succession planning processes and coordinated new director onboarding. He continued to enhance our global ethics and compliance program and championed our DEIA efforts as executive sponsor, including the expansion of our ERG program and focus on employee wellness. With responsibility for Tetra Tech’s Human Resources function, Mr. Hopson oversaw the implementation of enhanced employee benefits, rollout of a new performance management and compensation planning process, and spearheaded initiatives that led to industry-leading low voluntary turnover rates.

Mr. Argus drove performance across our global operations, resulting in record overall performance for FY 2024. He led his team to significant contributions to the overall increase in backlog and enhanced visibility for FY 2025. He also provided leadership on the identification, due diligence, and integration of several acquisitions, adding significant value and market position for the Company. In addition, he continued to expand the Fearless Entrepreneur program he founded to train early career employees to foster the future growth and success of our operations, which resulted in several hundred million dollars in new project wins throughout the world in FY 2024.

FY 2024 AIP Awards

Our NEOs received the AIP awards shown in the following table for FY 2024, based on their respective base salary at fiscal year-end (FYE) 2024, AIP opportunity, financial modifier, and individual performance modifier.

FY 2024 AIP Awards by NEO

Name	FY 2024 Base Salary ($)	Target Award Percentage (%)	Financial Modifier (CPF)	Individual Performance Modifier	AIP Award ($)
Mr. Batrack	1,225,000	150	1.4903	1.200	3,286,112
Mr. Burdick	675,000	100	1.4903	1.200	1,207,143
Dr. Shoemaker	600,000	80	1.4903	1.200	858,413
Mr. Hopson	550,000	85	1.4903	1.200	836,058
Mr. Argus	550,000	85	1.4860	1.000	694,705

FY 2024 LTI Award Program

Our LTI program provides variable incentive compensation to enhance the alignment of executive interests with stockholder interests, with an emphasis on performance-based vesting. Accordingly, the LTI awards granted in FY 2024 comprised the following.

PSU and RSU Percentages of FY 2024 LTI Awards

Type of Award

% of LTI (by value)

Vesting

Rationale

PSUs

60%

Determined at conclusion of a three-year performance period, with vesting determined 50% by EPS growth and 50% by relative TSR and subject to the holder’s continuous employment by Tetra Tech through the applicable vesting date

Performance-based; alignment with stockholder interests

RSUs

40%

25% per year, subject to the holder’s continuous employment by Tetra Tech through the applicable vesting date

Retention; facilitate stock ownership; alignment with stockholder interests

In FY 2024, the Compensation Committee granted the LTI awards shown in the following table. The target LTI value for each NEO was determined by the Compensation Committee and targeted within a competitive range of the market median, while internal equity, retention, and individual performance and role—among other factors—were also considered. The number of PSUs and RSUs awarded to each NEO was based on the closing price for shares of our common stock on November 16, 2023.

As a result of the required use of accounting methodology for determining grant date fair value in the Summary Compensation Table on page 60 of this proxy statement for PSUs with TSR vesting, certain total LTI values exceeded the corresponding target LTI

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values. The amounts listed in the table include the grant date fair value of PSUs, without adjustment for forfeitures. The actual number of shares issued can range from 0% to 200% of the target shares at the time of grant.

The performance condition component of the fair value of PSUs was determined based on the fair market value of our common stock on the date of grant. The market condition component of the fair value of the PSUs was determined as of the date of grant using the Monte Carlo simulation method, which uses multiple input variables to estimate the probability of meeting the performance objectives established for the award, including the volatility of our stock price and other assumptions appropriate for determining fair value. The amounts also include the grant date fair value of RSUs, without adjustment for forfeitures, using the closing price per share of our common stock on the grant date.

FY 2024 NEO LTI Awards

Name	Target LTI Value for FY 2024 ($)	PSUs (#)	PSUs ($)	RSUs (#)	RSUs ($)	Grant Date Fair Value ($)1
Mr. Batrack	7,000,000	127,520	5,191,084	85,015	2,793,933	7,985,017
Mr. Burdick	1,200,000	21,860	889,877	14,575	478,993	1,368,870
Dr. Shoemaker	1,000,000	18,215	741,457	12,145	399,133	1,140,590
Mr. Hopson	900,000	16,395	667,368	10,930	359,204	1,026,572
Mr. Argus	900,000	16,395	667,368	10,930	359,204	1,026,572

1 Accounting value as determined under Accounting Standards Codification (ASC) Topic 718.

LTI awards are generally granted annually after the close of the fiscal year. The Compensation Committee’s policy is to grant these equity awards following the public release of our fourth quarter and fiscal year financial results, during an open trading window, and to establish grant dates in advance.

Performance Stock Units: Three-Year Performance Period

The PSUs awarded to our NEOs cliff vest after a three-year performance period, subject to achievement of the applicable performance goals. Vesting is based 50% upon our EPS growth and 50% upon relative TSR performance. Since target LTI opportunity is set within a competitive range of the market median, TSR performance at the 50th percentile of the TSR peer group would result in payments from TSR vesting within a competitive range of the market median. If TSR performance is less than the 50th percentile, the resulting payments would be appropriately below market median.

With respect to the determination of EPS growth, PSUs will vest based on adjusted EPS achieved during the performance period. EPS growth will be measured by averaging EPS change on a point-to-point basis during the three-year performance period.

Our adjusted EPS is the fully diluted EPS from our continuing operations, which is then adjusted to reflect the impacts from the following in order to ensure consistency during the vesting period:

•

Goodwill impairment

•

Accounting changes requiring current and prior period adjustments due to materiality

•

Changes in newly issued or existing accounting principles

•

The settlement of tax audits for more or less than amounts previously recorded

•

Gains or losses from dispositions of subsidiaries and significant business lines

•

Impact of adjustments to earn out liabilities related to acquisitions

•

Costs incurred in connection with acquisitions, mergers, or debt restructurings

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Our relative TSR performance is measured as our percentile ranking within each TSR peer group. Equal weight is given to the industry peer group and the S&P 1000. With respect to the determination of relative TSR performance, PSUs will vest based on relative TSR performance achieved during the performance period.

	Vesting Credit (%)				Performance (percentile)
	0				Less than 25
	25				31.25
	50				37.5
	75				43.75
	100				50
	125				56.25
	150				62.5
	175				68.75
	200				Equal to or greater than 75

For determining our relative TSR for purposes of PSU vesting, the Compensation Committee uses a peer group that represents the industry in which we broadly compete for business and investor capital. The TSR peer group comprises the 16 U.S. public companies listed in the following table, satisfying objective criteria for industry classification and revenue size.

	ABM Industries, Inc.			Matrix, Inc.
	Aegion Corporation			McDermott International, Inc.
	Clean Harbors, Inc.			MYR Group Inc.
	Covanta Holding Corporation			Primoris Services Corporation
	Dycom Industries Inc.			Quanta Services, Inc.
	EMCOR Group, Inc.			Stantec Inc.
	KBR, Inc.			Team, Inc.
	MasTec, Inc.			Waste Connections, Inc.

Our TSR peer group is different than our compensation benchmarking peer group (listed in the Compensation Peer Group section on page 56 of this proxy statement), as it includes companies that may be too large or too small for our benchmarking peer group but are still viewed as competitors for investor capital.

Restricted Stock Units

All RSUs vest in equal annual installments over four years provided that the NEO remains employed by Tetra Tech through the applicable vesting date. These vesting provisions are designed to retain the services of the NEO for an extended duration.

Other Benefits

Nonqualified Deferred Compensation

Our NEOs are eligible to participate in our nonqualified Deferred Compensation Plan (DCP), which allows eligible employees to defer up to 80% of their base salary, AIP award, and PSU/RSU awards. The plan provides NEOs, other eligible employees, and nonemployee directors with a long-term capital accumulation opportunity because savings accumulate on a pretax basis. Participants may select from a number of investment options. The plan does not offer above-market interest rates. Deferrals are 100% vested. We do not make matching or any other contributions under the plan. Refer to the Nonqualified Deferred Compensation—FY 2024 table on page 64 in this proxy statement and the details set forth following that table for additional information regarding the DCP.

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Termination and Change in Control

None of our NEOs has an employment agreement, which reflects our pay for performance philosophy. Subject to the terms of the Tetra Tech, Inc. Change of Control Severance Plan (CIC Severance Plan) described in this section, if an NEO is no longer performing at the expected level, they can be terminated immediately without receiving a contractually guaranteed payment. Our NEOs are eligible to participate in the CIC Severance Plan, which supersedes all prior change in control agreements we had with our NEOs.

Our NEOs are eligible for severance payments upon termination by us “without cause” or by the executive “for good reason,” in each case, during the two-year period following (or, in the case of a termination without cause, 90-day period immediately preceding) a “change in control” of our Company (each, a “qualifying termination”), in accordance with the terms and conditions of the CIC Severance Plan. In the event of such a qualifying termination, the NEO would be eligible for (1) the following lump sum cash severance payments: (a) their current base salary plus target bonus for the fiscal year of employment termination times a multiple (the multiple is 2.0 in the case of Mr. Batrack, 1.5 in the cases of Mr. Burdick and Dr. Shoemaker, and 1.0 in the cases of Messrs. Hopson and Argus); (b) their prorated target bonus for the fiscal year of employment termination; (c) any earned but unpaid bonus for the fiscal year immediately preceding their employment termination; and (d) an amount equal to 102% of the cost of providing medical benefits (health, dental, and vision) to the NEO and the NEO’s dependents for 24 months (in the case of Mr. Batrack), 18 months (in the cases of Mr. Burdick and Dr. Shoemaker), and 12 months (in the cases of Messrs. Hopson and Argus); and (2) full vesting of outstanding unvested stock options, restricted stock, and RSUs that vest solely based on continued employment, and vesting of equity awards that vest in whole or in part on achievement of performance criteria based on actual performance results. No outstanding and unvested equity awards held by our NEOs would automatically vest upon a change in control.

In addition, if a participant’s employment is terminated because of their death or “disability” during the two years following a change in control, the NEO would receive their prorated target bonus for the fiscal year of employment termination and any earned but unpaid bonus for the preceding fiscal year. All payments are contingent on the execution of a release and continued compliance with certain restrictive covenants set forth in the CIC Severance Plan.

The payments and benefits provided for under the CIC Severance Plan would be reduced to the extent that they would trigger excise taxes under Section 4999 of the Internal Revenue Code, unless the NEO would be better off on an after-tax basis after taking into account all taxes, receiving the full amount of the payments and benefits. In this case, the payment and benefits would not be reduced. In no event is the Company obligated to provide any tax gross up or similar payment to the NEO.

Refer to the Potential Payments Upon Termination or Change in Control section on page 64 in this proxy statement for additional information regarding change in control events and outstanding awards granted to the NEOs.

Compensation Setting Process and Tools

Process

Each November, following the conclusion of our fiscal year on or about September 30, the Compensation Committee meets to determine the compensation for each NEO as follows: (1) the base salary is set for the succeeding year; (2) the variable AIP award is determined for the prior fiscal year and a new AIP award target is determined for the succeeding fiscal year; and (3) the LTI awards are granted for the succeeding fiscal year. Accordingly, in November 2023, the Compensation Committee determined the base salaries for FY 2024, the AIP awards for FY 2023 based on FY 2023 performance, and the LTI and AIP targets for FY 2024. In November 2024, the Compensation Committee determined the base salaries for FY 2025, the AIP awards for FY 2024 based on FY 2024 performance, and the LTI and AIP targets for FY 2025.

Use of Market Survey Data and Peer Group

The Compensation Committee began its FY 2024 process of deciding how to compensate our NEOs by considering the competitive market data provided by our independent compensation consultant, Meridian, and our human resources staff.

The Compensation Committee uses the market survey data as a reference point to target TDC at or around the median, also considering factors such as tenure, individual performance, the individual’s responsibilities, market factors, and succession and retention.

The Compensation Committee retains and does not delegate any of its exclusive power to determine all matters of executive compensation and benefits, although it seeks input and recommendations from the CEO and our human resources staff. Further, the Compensation Committee and the Audit Committee jointly determine the individual performance of the CFO. The Compensation Committee reports to the Board of Directors on the major items covered at each Compensation Committee meeting.

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Compensation Peer Group

The Compensation Committee worked with Meridian to develop a broad, size appropriate peer group with comparable annual revenue and market capitalization. This peer group consists of the companies listed below.

	AECOM			KBR, Inc.
	Booz Allen Hamilton, Inc.			Leidos Holdings, Inc.
	CACI International Inc.			Maximus, Inc.
	Clarivate, Plc			Parsons Corporation
	Dycom Industries Inc.			Science Applications Intl. Corp
	FTI Consulting, Inc.			Verisk Analytics, Inc.
	ICF International, Inc.

Independent Oversight and Expertise

Our Board believes that hiring and retaining effective executives and providing them with market competitive compensation are essential to the success of our Company and advance the interests of our stockholders. The Compensation Committee, which is comprised solely of independent directors, is responsible for overseeing our executive compensation program.

Under its charter, the Compensation Committee has the authority, in its sole discretion and at our expense, to obtain advice and assistance from external advisors. The Committee may select, retain and terminate any compensation consultant or other external advisor and has sole authority to approve any such advisor’s fees and other terms and conditions of the retention. In retaining its advisors, the Committee must consider each advisor’s independence from management.

Advisor Independence

Meridian did not provide services for our Company in FY 2024 other than the work undertaken for or at the request of the Compensation Committee.

Meridian and the Compensation Committee have the following protocols in place to ensure their independence from management:

•

The Compensation Committee has the sole authority to select, retain, and terminate Meridian, as well as to authorize Meridian’s fees and determine the other terms and conditions that govern the engagement

•

The Compensation Committee directs Meridian in the process of delivering and communicating its work product, including its analyses, findings, conclusions, and recommendations

•

In the performance of its duties, Meridian is accountable and reports directly to the Compensation Committee

•

The Compensation Committee may consult with Meridian at any time, with or without members of management present, at the Compensation Committee’s sole discretion

In accordance with regulatory requirements, the Compensation Committee evaluated the following six factors to assess independence and conflicts of interest before it engaged Meridian to perform work in FY 2024:

•

The provision of other services to us by Meridian

•

The amount of fees received by Meridian from us, as a percentage of Meridian’s total revenues

•

Meridian’s policies and procedures designed to prevent conflicts of interest

•

Any business or personal relationship between a member of the Compensation Committee and the regular members of Meridian’s executive compensation team who serve us

•

Any of our stock owned by the regular members of Meridian’s executive compensation team who serve us

•

Any business or personal relationships between our executive officers and the regular members of Meridian’s executive compensation team who serve us

The Compensation Committee also obtained a representation letter from Meridian addressing these six factors and certain other matters related to its independence. Based on the Compensation Committee’s evaluation of these factors and the representations from Meridian, the Compensation Committee concluded that Meridian is an independent adviser and has no conflicts of interest with us.

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Compensation Discussion and Analysis

Stock Ownership Guidelines

To further the goal of aligning the interests of executive officers and nonemployee directors with those of stockholders, we maintain a policy regarding minimum ownership of our shares. These ownership guidelines currently call for the following:

•

The CEO to own shares having a value equal to at least six times the CEO’s base salary

•

Each EVP to own shares having a value equal to at least three times base salary

•

Each SVP to own shares having a value equal to at least two times the executive officer’s base salary

•

Each nonemployee director to own shares having a value equal to at least five times the nonemployee director’s annual base cash retainer

Until an executive officer’s or nonemployee director’s stock ownership requirement is met, the executive officer or nonemployee director must retain at least 75% of gain shares resulting from the exercise of a stock option or vesting of a performance share, PSU award, or RSU award. With respect to stock options, “gain shares” means the total number of shares of common stock being exercised less the number of shares, if any, used in the case of a cashless exercise to pay for the exercise price. With respect to PSU awards and RSU awards, gain shares are the total number of shares of common stock subject to any such equity award that vests. Gain shares do not include shares of common stock used to satisfy tax withholding obligations.

Each executive officer and nonemployee director has five years to attain the required ownership level. In addition to shares of common stock, unvested RSUs count in determining stock ownership for purposes of the stock ownership guidelines. An executive officer or nonemployee director who fails to comply with the stock ownership guidelines may be required to use one third of any net annual cash bonus or net annual retainer, as applicable, to purchase shares of our stock. In addition, in the event of non-compliance, the Compensation Committee may exercise its discretion to declare an executive officer or nonemployee director ineligible to receive equity grants under our equity plans until such time as compliance is achieved.

As of FYE 2024, all our directors and executive officers have met our stock ownership guidelines, taking into account the phase-in requirements of the policy if applicable to such person, helping ensure the alignment of their interests with those of our stockholders.

Clawback Policy

We have adopted a Dodd-Frank Wall Street Reform and Consumer Protection Act-compliant compensation recoupment policy in accordance with SEC and listing exchange requirements. In the event we are required to prepare an accounting restatement, we will recover any compensation received after the effective date by any current or former executive officer that is based wholly or in part upon the attainment of a financial reporting measure.

Policies and Practices Related to the Timing of Option and SAR Awards

We did not grant options, stock appreciation rights (SARs) or similar option-like instruments during FY24 and do not currently intend to grant such awards to our directors and officers as part of our compensation program. Accordingly, we do not have a formal written policy in place with regard to the timing of grants of options, stock appreciation rights (SARs) or similar option-like instruments in relation to the disclosure of material nonpublic information.

Insider Trading, Anti Hedging, and Anti Pledging Policy

In addition to the general provisions of our Insider Trading Policy, which prohibits all employees and directors from trading in our securities while in possession of material nonpublic information, the policy also strictly prohibits our employees and directors from engaging in transactions in our securities involving puts, calls, or other derivative securities on an exchange or in any other organized market, selling our securities “short,” or entering into hedging or similar arrangements (e.g., exchange funds) involving our securities. The policy also prohibits our employees and directors from pledging our securities as collateral for a loan or holding our securities in a margin account.

Tax and Accounting Implications of Executive Compensation

The Compensation Committee considers the tax and accounting consequences to the Company and our NEOs as one factor among many when structuring executive compensation.

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Compensation Committee Report

The Compensation Committee of the Board of Directors has reviewed and discussed the CD&A required by Item 402(b) of Regulation S-K with management and, based on its review and these discussions, has recommended to the Board of Directors that the CD&A be included or incorporated by reference into our FY 2024 Annual Report on Form 10-K and 2025 proxy statement.

The Compensation Committee welcomes feedback regarding our executive compensation program. Stockholders may communicate with the individual members of the Committee by writing to the Compensation Committee Chair, c/o Corporate Secretary, Tetra Tech, 3475 E. Foothill Boulevard, Pasadena, California 91107.

Respectfully submitted by:

Kirsten M. Volpi, Chair
Christiana Obiaya
Kimberly E. Ritrievi

This Compensation Committee Report does not constitute soliciting material and should not be deemed filed or incorporated by reference into any of our filings under the Securities Act or the Exchange Act, whether made before or after the date hereof, unless specifically incorporated by reference therein.

Compensation Committee Interlocks and Insider Participation

No member of the Compensation Committee was at any time during FY 2024 one of our officers or employees, and no member of the Compensation Committee had any relationship with us requiring disclosure under Item 404 of Regulation S-K. During FY 2024, none of our executive officers served on the board of directors or compensation committee of any other company, which company has or had one or more executive officers who served as a member of our Board of Directors or Compensation Committee.

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Summary Compensation Table

The following table shows the compensation earned by or awarded to our NEOs during FYs 2024, 2023, and 2022, in accordance with SEC regulations. Compensation as shown in the table does not necessarily reflect the compensation realized by our NEOs for those years. For example, the amounts for 2024 set forth in the Stock Awards column relating to PSUs do not represent the actual amounts realized by our NEOs; rather they represent the aggregate grant date fair value for financial reporting purposes of those PSUs, which cliff vest subject to achievement of the applicable performance goals (based on 50% by EPS growth and 50% by relative TSR) at the end of a three year performance period and ultimately may result in no such compensation being realized by the NEO.

Summary of Executive Compensation by NEO

Name and Principal Position	Year	Salary ($)1	Bonus	Stock Awards ($)2	Non-Equity Incentive Plan Compensation ($)3	All Other Compensation ($)4	Total ($)
Mr. Batrack Chairman, CEO	2024	1,220,673	—	7,985,017	3,286,112	68,539	12,560,342
	2023	1,196,154	—	6,859,003	3,767,040	63,321	11,885,517
	2022	1,204,327	—	6,281,608	2,783,549	62,413	10,331,897
Mr. Burdick EVP, CFO	2024	666,346	—	1,368,870	1,207,143	49,737	3,292,095
	2023	618,846	200,000	1,143,141	1,046,400	50,046	3,058,433
	2022	603,269	—	1,128,581	791,915	45,318	2,569,083
Dr. Shoemaker EVP, Chief Innovation and Sustainability Officer	2024	597,404	—	1,140,590	858,413	44,040	2,640,447
	2023	585,000	100,000	1,143,141	897,811	41,788	2,767,740
	2022	603,269	—	1,128,581	791,915	41,349	2,565,114
Mr. Hopson SVP, General Counsel, and Secretary	2024	543,077	—	1,026,572	836,058	46,886	2,452,593
	2023	504,615	100,000	914,466	800,496	46,371	2,365,948
	2022	484,808	—	920,707	602,820	45,095	2,053,429
Mr. Argus SVP and President, GSG and CIG	2024	543,077	—	1,026,572	694,705	47,520	2,311,874
	2023	504,615	—	914,466	717,484	53,976	2,190,541
	2022	484,808	—	920,707	541,474	47,651	1,994,640

1 Amounts include any portions of salary deferred under our DCP. Increases in base salary, if any, became effective in November of each year and were not retroactive to the beginning of the fiscal year. Accordingly, for a portion of a fiscal year, an NEO who received a base salary increase received base salary at the prior fiscal year’s base salary rate.

2 The amounts in this column reflect the aggregate grant date fair value of stock awards granted during the applicable fiscal year, without adjustment for forfeitures, and do not reflect compensation realized by our NEOs. For values realized by our NEOs during FY 2024, see the Value Realized on Vesting column of the Options Exercised and Stock Vested—FY 2024 table on page 63 of this proxy statement. Amounts in 2024 include the grant date fair value of PSUs, without adjustment for forfeitures, which are payable at the end of a three-year performance period provided that the performance objectives are achieved as of the end of the period. The actual number of shares issued can range from 0% to 200% of the target shares at the time of grant. The performance objectives that determine the number of shares that may be earned for the PSUs are (a) as to 50% of the award, growth in EPS, which is a performance condition under FASB ASC Topic 718, and (b) as to 50% of the award, TSR, which is a market condition under FASB ASC Topic 718, relative to the TSR of (i) 16 companies objectively determined based on GICS code and revenue size (25% of award) and (ii) the S&P 1000 (25% of award), in each case computed over the three-year performance period. The performance condition component of the fair value of PSUs was determined based on the fair market value of our common stock on the date of grant. The market condition component of the fair value of the PSUs was determined as of the date of grant using the Monte Carlo simulation method, which uses multiple input variables to estimate the probability of meeting the performance objectives established for the award, including the volatility of our stock price and other assumptions appropriate for determining fair value. Based on those computations, the grant date fair value of the PSU awards granted on November 21, 2023, to each NEO were $32.86 per share for the performance condition component and $42.55 per share for the market condition component. The maximum grant date fair values of the PSUs granted in FY 2023 (200% vesting) were $10,382,165, $1,779,754, $1,482,914, $1,334,737, and $1,334,737 for Mr. Batrack, Mr. Burdick, Dr. Shoemaker, Mr. Hopson, and Mr. Argus, respectively. Amounts in 2024 also include the grant date fair value of RSUs, computed in accordance with FASB ASC Topic 718 and without adjustment for forfeitures, using the closing price per share of our common stock on the grant date ($32.86 per share).

3 The amounts listed in this column for FY 2024 reflect the cash awards paid to the NEOs for FY 2024 performance, as further described in the Compensation Discussion and Analysis section on page 39 of this proxy statement and the Grants of Plan Based Awards—FY 2024 table below. The amounts listed in this column for FYs 2023 and 2022 reflect the cash awards paid to the NEOs for performance in those fiscal years.

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4 Figures in this column consist of the employer contribution made on behalf of each of the NEOs to our health and welfare benefits and our qualified retirement plan, as well as the reimbursements for vehicle use, financial and tax planning, memberships, and annual physical examinations. Amounts for Mr. Batrack are enumerated in the table below:

	Company Contribution to 401(k) Plan				Company Contribution to Health and Welfare Benefits				Automobile Allowance				Memberships				Financial and Tax Planning
	$18,300				$15,651				$10,800				$19,788				$4,000

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Grants of Plan Based Awards–FY 2024

The following table provides information regarding grants of plan-based incentive awards made to our NEOs during FY 2024.

		Estimated Possible Payouts under Non-Equity Incentive Plan Awards			Estimated Possible Payouts under Equity Incentive Plan Awards			All Other Stock Awards: Shares of Stock or Units (#)	All Other Option Awards: Securities Underlying Options (#)	Exercise or Base Price of Option Awards ($)	Grant Date Fair Value of Stock and Option Awards ($)
Name	Grant Date	Threshold ($)	Target ($)	Maximum ($)	Threshold (#)	Target (#)	Maximum (#)	All Other Stock Awards: Shares of Stock or Units (#)	All Other Option Awards: Securities Underlying Options (#)	Exercise or Base Price of Option Awards ($)	Grant Date Fair Value of Stock and Option Awards ($)
Mr. Batrack	1	0	1,837,500	3,675,000
	11/21/232				0	127,520	255,040				5,191,084
	11/21/233							85,015			2,793,933
Total											7,985,017
Mr. Burdick	1	0	675,000	1,350,000
	11/21/232				0	21,860	43,720				889,877
	11/21/233							14,575			478,993
Total											1,368,870
Dr. Shoemaker	1	0	468,000	936,000
	11/21/232				0	18,215	36,430				741,457
	11/21/233							12,145			399,133
Total											1,140,590
Mr. Hopson	1	0	467,500	934,000
	11/21/232				0	16,395	32,790				667,368
	11/21/233							10,930			359,204
Total											1,026,572
Mr. Argus	1	0	467,500	934,000
	11/21/232				0	16,395	32,790				667,368
	11/21/233							10,930			359,204
Total											1,026,572

1 This row represents the possible AIP awards for FY 2024. Additional information about these payments appears in the Compensation Discussion and Analysis section on page 39 of this proxy statement. The actual award payments, as determined by the Compensation Committee on November 20, 2024, are included in the Non-Equity Incentive Plan Compensation ($) column of the Summary Compensation Table on page 60 of this proxy statement. The target and maximum values are calculated by multiplying (a) 150% and 300%, respectively, by Mr. Batrack’s annual base salary; (b) 100% and 200%, respectively, by Mr. Burdick’s annual base salary; (c) 80% and 160%, respectively, by Dr. Shoemaker’s annual base salary; and (d) 85% and 170%, respectively, by Mr. Argus’s and Mr. Hopson’s annual base salaries, each as in effect at the end of FY 2024.

2 The amounts shown in this row reflect, in share amounts, the threshold, target, and maximum potential payouts of PSUs, as further discussed in the Compensation Discussion and Analysis section on page 39 of this proxy statement. The PSUs were granted under the 2018 Equity Incentive Program (EIP) and cliff vest in shares of our common stock after the end of a three-year performance period, subject to the achievement of the applicable performance goals. Vesting, from 0% to 200% of the award, is completely at risk and is based 50% upon our EPS growth and 50% upon our relative TSR. For additional details on the grant date fair value of these PSUs, see footnote (3) of the Summary Compensation Table on page 60 of this proxy statement. Dividend equivalents are payable on the underlying PSU shares, but only to the extent that the applicable performance goals are subsequently satisfied and the PSUs vest.

3 The amounts shown in this row reflect the awards of RSUs, as further discussed in the Compensation Discussion and Analysis section on page 39 of this proxy statement. The RSUs were granted under the 2018 EIP and vest as to 25% of the award on November 30, 2025, and on each anniversary of that date until fully vested, subject to the holder’s continuous employment by us through the applicable vesting date. For additional details on the grant date fair value of these RSUs, see footnote (3) of the Summary Compensation Table on page 60 of this proxy statement.

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Outstanding Equity Awards at FYE 2024

The following table provides information regarding NEO equity awards outstanding as of September 29, 2024, the FYE 2024.

	Option Awards				Stock Awards
Name	Number of Securities underlying Unexercised Options Exercisable (#)	Securities underlying Unexercised Options Unexercisable (#)	Option Exercise Price ($)	Option Expiration Date	Shares or Units of Stock Not Vested (#)	Market Value of Shares or Units of Stock Not Vested ($)1	Unearned Shares, Units, or Other Rights Not Vested (#)	Market or Payout Value of Unearned Shares, Units, or Other Rights Not Vested ($)1
Mr. Batrack	—	—			16,3902	760,496
					28,0603	1,301,984
					57,0404	2,646,656
					85,0155	3,944,696
							84,1856	3,906,184
							114,0857	5,293,544
							127,5208	5,916,928
Total	—	—			186,505	8,653,832	325,790	15,116,656
Mr. Burdick	—	—			3,6852	170,984
					5,0403	233,856
					9,5054	441,032
					14,5755	676,280
							15,1256	701,800
							19,0157	882,296
							21,8608	1,014,304
Total	—	—			32,805	1,522,152	56,000	2,598,400
Dr. Shoemaker	—	—
					3,6852	170,984
					5,0403	233,856
					9,5054	441,032
					12,1455	563,528
							15,1256	701,800
							19,0157	882,296
							18,2158	845,176
Total	—	—			30,375	1,409,400	52,355	2,429,272
Mr. Hopson	—	—			3,0702	142,448
					4,1103	190,704
					7,6054	352,872
					10,9305	507,152
							12,3406	572,576
							15,2107	705,744
							16,3958	760,728
Total	—	—			25,715	1,193,176	43,945	2,039,048

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	Option Awards				Stock Awards
Name	Number of Securities underlying Unexercised Options Exercisable (#)	Securities underlying Unexercised Options Unexercisable (#)	Option Exercise Price ($)	Option Expiration Date	Shares or Units of Stock Not Vested (#)	Market Value of Shares or Units of Stock Not Vested ($)1	Unearned Shares, Units, or Other Rights Not Vested (#)	Market or Payout Value of Unearned Shares, Units, or Other Rights Not Vested ($)1
Mr. Argus	—	—			2,8652	132,936
					4,1103	190,704
					7,6054	352,872
					10,9305	507,152
							12,3406	572,576
							15,2107	705,744
							16,3958	760,728
Total	—	—			25,510	1,183,664	43,945	2,039,048

1 Market value calculated based on a stock price of $46.40, the closing price of our common stock on September 27, 2024, the last trading day of our 2024 fiscal year.

2 Granted on 11/19/20; vests 25% on 11/18/21 and 25% annually for next three years.

3 Granted on 11/23/21; vests 25% on 11/18/22 and 25% annually for next three years.

4 Granted on 11/16/22; vests 25% on 11/18/23 and 25% annually for next three years.

5 Granted on 11/21/23; vests 25% on 11/30/24 and 25% annually for next three years.

6 Granted on 11/23/21; cliff vesting following three-year performance period based on EPS growth and relative TSR.

7 Granted on 11/16/22; cliff vesting following three-year performance period based on EPS growth and relative TSR

8 Granted on 11/21/23; cliff vesting following three-year performance period based on EPS growth and relative TSR.

Options Exercised and Stock Vested–FY 2024

The following table shows the number of shares acquired by each of the NEOs during FY 2024 through exercising stock options and the vesting of PSUs and RSUs. The table also presents the value realized upon options being exercised and PSUs and RSUs being vested, as calculated, in the case of stock options, based on the difference between the market price of our common stock at exercise and the option exercise price and, as calculated, in the case of PSUs and RSUs, based on the closing price per share of our common stock on the Nasdaq Global Select Market on the vesting date.

	Option Awards		Stock Awards
Name	Shares Acquired on Exercise (#)	Value Realized on Exercise ($)	Shares Vested (#)1	Value Realized on Vesting ($)
Mr. Batrack	—	—	239,505	7,882,140
Mr. Burdick	—	—	51,400	1,691,308
Dr. Shoemaker	55,805	1,829,092	32,435	1,068,042
Mr. Hopson	—	—	42,200	1,388,510
Mr. Argus	—	—	39,885	1,312,398

1 Consists of PSUs and RSUs

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Nonqualified Deferred Compensation–FY 2024

The following table shows each NEO’s contributions and earnings during FY 2024 and account balance as of September 29, 2024, under our DCP.

Name1	Executive Contributions in Last Fiscal Year ($)2	Tetra Tech Contributions in Last Fiscal Year ($)	Aggregate Earnings in Last Fiscal Year ($)3	Aggregate Withdrawals or Distributions ($)4	Aggregate Balance at Last Fiscal Year End ($)5
Mr. Batrack	99,410	—	10,298,067	—	32,175,415
Mr. Burdick	—	—	1,332,657	383,902	6,856,747
Dr. Shoemaker	857,618	—	716,406	—	3,627,479

1 Mr. Hopson and Mr. Argus are not included in this table because they do not participate in the DCP.

2 These amounts were included in the Salary ($) and/or Non-Equity Incentive Plan Compensation ($) columns, as applicable, of the Summary Compensation Table on page 60 of this proxy statement.

3 None of the amounts are included in the Summary Compensation Table on page 60 of this proxy statement because plan earnings were not preferential or above market. The amount for Mr. Batrack includes $9,814,558, representing the stock price appreciation of Tetra Tech stock units deferred into the DCP. There is no guarantee that the earnings associated with the deferred Tetra Tech stock units will be realized by Mr. Batrack.

4 These amounts were included in the Salary ($) and/or Non-Equity Incentive Plan Compensation ($) columns, as applicable, of the Summary Compensation Table on page 60 of this proxy statement at the time such compensation was earned.

5 As of September 27, 2024, which was the last business day of FY 2024. The amount for Mr. Batrack includes $28,472,896, representing the value of Tetra Tech stock units deferred into the DCP.

The DCP is an unfunded and unsecured deferred compensation arrangement designed to allow the participants to defer a percentage of their base salary, bonuses, director’s fees, and equity awards other than options and invest the deferrals in a manner similar to the way in which our 401(k) plan operates, but without regard to the maximum deferral limitations imposed on 401(k) plans by the Internal Revenue Code. The DCP is designed to comply with Section 409A of the Internal Revenue Code. As required by applicable law, participation in the DCP is limited to our directors and a group of our management employees, which includes our NEOs. Since the adoption of the DCP by the Board of Directors in 2006, we have not made any contribution on behalf of any director or executive officer.

Amounts deferred by each participant pursuant to the DCP are credited to a bookkeeping account maintained on behalf of that participant. Amounts credited to each participant under the DCP are periodically adjusted for earnings and/or losses at rates equal to one or more of the measurement funds selected by the Compensation Committee and elected by participants. Stock unit deferrals represent shares of Tetra Tech common stock and may not be diversified into other investment options.

Potential Payments upon Termination or Change in Control

We do not enter into employment agreements with our NEOs (or any executive officers). The CEO’s employment may be terminated at any time at the discretion of the Board of Directors. The employment of the other NEOs may be terminated at any time by the CEO with the Board’s concurrence. Our NEOs are eligible to participate in the CIC Severance Plan.

Under the CIC Severance Plan, if an NEO’s employment is terminated by us “without cause” or by the NEO “with good reason,” in each case, within two years following (or, in the case of a termination without cause, a 90-day period immediately preceding) a change in control (each, a “qualifying termination”), we will pay or provide the following lump sum cash severance payments:

•

Severance pay equal to their current base salary plus a target bonus for the fiscal year employment terminates times a multiple (2.0 in the case of Mr. Batrack, 1.5 in the cases of Mr. Burdick and Dr. Shoemaker, and 1.0 in the cases of Messrs. Hopson and Argus)

•

A pro rata target bonus for the year of termination, based on the number of days the NEO worked during the year

•

The bonus the NEO earned for the year preceding the year of termination if such bonus has not yet been paid

•

A payment equal to 102% of the cost of providing medical benefits (health, dental, and vision) to the NEO and their dependents substantially similar to those provided immediately prior to such termination date for 24 months (in the case of the Mr. Batrack), 18 months (in the cases of Mr. Burdick and Dr. Shoemaker), or 12 months (in the cases of Messrs. Hopson and Argus)

In addition, pursuant to the terms of the CIC Severance Plan, in connection with a qualifying termination, all outstanding and unvested stock options, restricted stock, and RSUs that vest solely based on continued employment will fully vest, and equity awards

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that vest in whole or in part on achievement of performance criteria will vest based on actual performance results. No outstanding or unvested equity awards held by our NEOs will automatically vest upon a change in control.

Under the terms of the CIC Severance Plan, if an NEO’s employment is terminated because of their death or disability, in each case, within two years following a change in control, we will pay a pro rata target bonus for the year of termination, based on the number of days the NEO worked during the year, together with the bonus the NEO earned for the year preceding the year of termination if such bonus has not yet been paid.

All severance payments described above are contingent on the execution of a release and continued compliance with the restrictive covenants set forth in the CIC Severance Plan (i.e., confidentiality and non-solicitation of employees, clients, suppliers, licensees, or business relations for a post termination period of 24 months for Mr. Batrack, 18 months for Mr. Burdick and Dr. Shoemaker, and 12 months for Messrs. Hopson and Argus).

Each NEO will also be paid or provided with any unpaid base salary, accrued vacation, and unreimbursed expenses through the date of their employment termination, together with any benefits to which the NEO is entitled under our benefits programs.

The payments and benefits provided for under the CIC Severance Plan will be reduced to the extent that they would trigger excise taxes under Section 4999 of the Internal Revenue Code, unless an NEO would be better off on an after-tax basis, after taking into account all taxes, receiving the full amount of the payments and benefits. In that case, the payments and benefits will not be reduced. In no event is the Company obligated to provide any tax gross up or similar payment to the NEOs.

A “change in control” for purposes of the CIC Severance Plan generally consists of one or more of the following events:

•

An acquisition by any person of beneficial ownership of securities representing 50% or more of the combined voting power of Tetra Tech’s voting securities (on one date or during any 12-month period)

•

The consummation of a merger, reorganization, or consolidation if Tetra Tech’s stockholders (together with any trustee or fiduciary acquiring securities under any benefit plan) do not own more than 50% of the combined voting power of the merged, reorganized, or consolidated Company’s then outstanding securities (other than a recapitalization in which no person acquires more than 50% of the combined voting power of our outstanding securities)

•

The consummation of a sale of all or substantially all Tetra Tech’s assets (other than a sale to an entity in which our stockholders own 50% or more of the voting securities of such entity)

“Good reason” for purposes of the CIC Severance Plan generally includes any of the following actions by Tetra Tech:

•

A material diminution of the NEO’s base salary, annual bonus opportunity, or both

•

A material diminution in the NEO’s authority, duties, or responsibilities

•

A material diminution in the budget over which the NEO retains authority

•

A material change in the geographic location at which the NEO must perform their services

An NEO will be entitled to terminate their employment for good reason only if they have provided Tetra Tech with notice of the occurrence of a condition described above within 60 days of its initial existence and we have failed to remedy such condition within 30 days after receipt of the notice. An NEO’s employment will be deemed to have been terminated following a change in control by the NEO for good reason if the NEO terminates their employment prior to a change in control for good reason if a good reason condition occurs at the direction of a person or entity who has entered into an agreement with Tetra Tech, the consummation of which will constitute a change in control.

“Cause” means one of the following:

•

The willful and continued failure of the NEO to perform substantially their duties (other than a failure resulting from incapacity due to physical or mental illness) after a written demand for substantial performance is delivered to the NEO by the Board of Directors or CEO that specifically identifies the manner in which the Board of Directors or CEO believes that the NEO has not substantially performed their duties

•

The willful engaging by the NEO in illegal conduct or gross misconduct that is materially and demonstrably injurious to the Company

For purposes of this definition of “cause,” no act or failure to act on the part of an NEO will be considered “willful” unless it is done, or is not done, by the NEO in bad faith or without reasonable belief that the NEO’s action or omission was in Tetra Tech’s best interests. Any act, or failure to act, based upon authority given pursuant to a resolution duly adopted by the Board of Directors or

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upon the instructions of our CEO, one of our executive officers or upon the advice of our legal counsel will be conclusively presumed to be done, or not done, by the NEO in good faith and in our best interests.

Assumptions Regarding the Tables

The tables in this section were prepared as though a change in control occurred on September 27, 2024 (the last business day of Tetra Tech’s most recent fiscal year) and the employment of each of our NEOs was terminated on that date. For purposes of any calculations involving equity awards, we have used the closing share price of Tetra Tech common stock on September 27, 2024, which was $46.40. Tetra Tech is required by the SEC to use these assumptions. The NEOs’ employment was not terminated on September 27, 2024, however, and a change in control did not occur on that date. As a result, there can be no assurance that a termination of employment, a change in control, or both would produce the same or similar results as those described if either or both of them occurred on any other date or at any other price, or if any assumption used in this disclosure is not correct in fact. All amounts presented in the tables below are estimates only. The following are the equity award and annual bonus assumptions:

•

Stock options that vest due to an employment termination “without cause” or “with good reason” within two years following (or, in the case of a termination without cause, 90 days immediately preceding) a change in control are valued based on their option spread (i.e., the excess of fair market value of a share of common stock on September 27, 2024, $46.40 over the exercise price)

•

PSUs and RSUs that vest due to an employment termination “without cause” or “with good reason” within two years following (or, in the case of a termination without cause, 90 days immediately preceding) a change in control are valued based on the number of shares subject to such award multiplied by the fair market value of a share of common stock on September 27, 2024 ($46.40)

•

PSUs are assumed to vest at 100% of target

Given that each of the NEO’s employment is assumed to have been terminated on September 27, 2024, for purposes of the tables in this section, any annual bonus for that year would have been earned as of that date under the terms of Tetra Tech’s bonus program. As a result, no amounts with respect to prorated bonuses for the year of termination of employment have been included in the tables

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Mr. Batrack

Payment Type	Change in Control ($)	Termination without Cause or with Good Reason in Connection with a Change in Control ($)	Termination Due to Death or Disability in Connection with a Change in Control ($)1	Termination Due to Resignation without Good Reason in Connection with a Change in Control ($)2	Termination Due to Cause in Connection with a Change in Control ($)2
Severance Benefits3	—	5,390,000	—	—	—
Prorated Bonus	—	—	—	—	—
Health Benefits	—	31,296	—	—	—
Accelerated Vesting of Unvested Stock Options4	—	—	—	—	—
Accelerated Vesting of Unvested Performance Shares/PSUs4	—	15,116,656	—	—	—
Accelerated Vesting of Unvested RSUs4	—	8,653,832	—	—	—
Golden Parachute Cutback (if any)	—	—	—	—	—
Total	—	29,191,784	—	—	—

1 The only cash compensation payable is the prorated bonus, together with the bonus earned from the prior year if not yet paid, any unpaid base salary through the date of termination, and other payments available from life insurance or disability plans.

2 The only cash compensation payable is any unpaid base salary through the date of termination.

3 Payable in a cash lump sum payment.

4 Does not include the value associated with options to purchase our common stock, performance shares, and RSUs that were vested as of September 27, 2024. No PSUs were vested as of that date. See the Outstanding Equity Awards at FYE 2024 section on page 62 of this proxy statement for information regarding outstanding vested stock options. See the Options Exercised and Stock Vested—FY 2024section on page 63 of this proxy statement for information regarding performance shares and RSUs that vested in FY 2024.

Mr. Burdick

Payment Type	Change in Control ($)	Termination without Cause or with Good Reason in Connection with a Change in Control ($)	Termination Due to Death or Disability in Connection with a Change in Control ($)1	Termination Due to Resignation without Good Reason in Connection with a Change in Control ($)2	Termination Due to Cause in Connection with a Change in Control ($)2
Severance Benefits3	—	1,181,250	—	—	—
Prorated Bonus	—	—	—	—	—
Health Benefits	—	15,540	—	—	—
Accelerated Vesting of Unvested Stock Options4	—	—	—	—	—
Accelerated Vesting of Unvested Performance Shares/PSUs4	—	2,598,400	—	—	—
Accelerated Vesting of Unvested RSUs4	—	1,522,152	—	—	—
Golden Parachute Cutback (if any)	—	—	—	—	—
Total	—	5,317,342	—	—	—

2 The only cash compensation payable is any unpaid base salary through the date of termination.

3 Payable in a cash lump sum payment.

4 Does not include the value associated with options to purchase our common stock, performance shares, and RSUs that were vested as of September 27, 2024. No PSUs were vested as of that date. See the Outstanding Equity Awards at FYE 2024 section on page 62 of this proxy statement for information regarding outstanding vested stock options. See the Options Exercised and Stock Vested—FY 2024 section on page 63 of this proxy statement for information regarding performance shares and RSUs that vested in FY 2024.

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Dr. Shoemaker

Payment Type	Change in Control ($)	Termination without Cause or with Good Reason in Connection with a Change in Control ($)	Termination Due to Death or Disability in Connection with a Change in Control ($)1	Termination Due to Resignation without Good Reason in Connection with a Change in Control ($)2	Termination Due to Cause in Connection with a Change in Control ($)2
Severance Benefits3	—	1,050,000	—	—	—
Prorated Bonus	—	—	—	—	—
Health Benefits	—	15,504	—	—	—
Accelerated Vesting of Unvested Stock Options4	—	—	—	—	—
Accelerated Vesting of Unvested Performance Shares/PSUs4	—	2,429,272	—	—	—
Accelerated Vesting of Unvested RSUs4	—	1,409,400	—	—	—
Golden Parachute Cutback (if any)	—	—	—	—	—
Total	—	4,904,176	—	—	—

2 The only cash compensation payable is any unpaid base salary through the date of termination.

3 Payable in a cash lump sum payment.

4 Does not include the value associated with options to purchase our common stock, performance shares, and RSUs that were vested as of September 27, 2024. No PSUs were vested as of that date. See the Outstanding Equity Awards at FYE 2024 section on page 62 of this proxy statement for information regarding outstanding vested stock options. See the Options Exercised and Stock Vested—FY 2024 section on page 63 of this proxy statement for information regarding performance shares and RSUs that vested in FY 2024.

Mr. Hopson

Payment Type	Change in Control ($)	Termination without Cause or with Good Reason in Connection with a Change in Control ($)	Termination Due to Death or Disability in Connection with a Change in Control ($)1	Termination Due to Resignation without Good Reason in Connection with a Change in Control ($)2	Termination Due to Cause in Connection with a Change in Control ($)2
Severance Benefits3	—	962,500	—	—	—
Prorated Bonus	—	—	—	—	—
Health Benefits	—	6,720	—	—	—
Accelerated Vesting of Unvested Stock Options4	—	—	—	—	—
Accelerated Vesting of Unvested Performance Shares/PSUs4	—	2,039,048	—	—	—
Accelerated Vesting of Unvested RSUs4	—	1,193,176	—	—	—
Golden Parachute Cutback (if any)	—	—	—	—	—
Total	—	4,201,444	—	—	—

2 The only cash compensation payable is any unpaid base salary through the date of termination.

3 Payable in a cash lump sum payment.

4 Does not include the value associated with options to purchase our common stock, performance shares, and RSUs that were vested as of September 27, 2024. No PSUs were vested as of that date. See the Outstanding Equity Awards at FYE 2024 section on page 62 of this proxy statement for information regarding outstanding vested stock options. See the Options Exercised and Stock Vested—FY 2024 section on page 63 of this proxy statement for information regarding performance shares and RSUs that vested in FY 2024.

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Mr. Argus

Payment Type	Change in Control ($)	Termination without Cause or with Good Reason in Connection with a Change in Control ($)	Termination Due to Death or Disability in Connection with a Change in Control ($)1	Termination Due to Resignation without Good Reason in Connection with a Change in Control ($)2	Termination Due to Cause in Connection with a Change in Control ($)2
Severance Benefits3	—	926,500	—	—	—
Prorated Bonus	—	—	—	—	—
Health Benefits	—	10,452	—	—	—
Accelerated Vesting of Unvested Stock Options4	—	—	—	—	—
Accelerated Vesting of Unvested Performance Shares/PSUs4	—	2,039,048	—	—	—
Accelerated Vesting of Unvested RSUs4	—	1,183,664	—	—	—
Golden Parachute Cutback (if any)	—	—	—	—	—
Total	—	4,195,664	—	—	—

1 The only cash compensation payable is the prorated bonus, together with the bonus earned from the prior year if not yet paid, any unpaid base salary through the date of termination and other payments available from life insurance or disability plans.

2 The only cash compensation payable is any unpaid base salary through the date of termination.

3 Payable in a cash lump sum payment.

4 Does not include the value associated with options to purchase our common stock, performance shares, and RSUs that were vested as of September 27, 2024. No PSUs were vested as of that date. See the Outstanding Equity Awards at FYE 2024 section on page 62 of this proxy statement for information regarding outstanding vested stock options. See the Options Exercised and Stock Vested—FY 2024 section on page 63 of this proxy statement for information regarding performance shares and RSUs that vested in FY 2024.

Equity Compensation Plan Information

The following table provides information as of September 29, 2024, about the shares of Tetra Tech common stock that may be issued under our existing equity compensation plans. All of our existing plans have been approved by our stockholders. A majority of our employees are eligible to participate in the Employee Stock Purchase Plan (ESPP) and the 2018 EIP, subject to certain limitations, terms, and conditions.

Equity Compensation Plans Approved by Stockholders1
Securities to be Issued upon Exercise of Outstanding Options, Warrants, and Rights (#)2	Weighted Average Exercise Price of Outstanding Options, Warrants, and Rights3	Securities Remaining Available for Future Issuance under Equity Compensation Plans (excluding securities reflected in the first column) (#)
331,580	$8.41	22,528,4604

1 Consists of the 2018 EIP, the 2015 EIP (under which options and awards are no longer granted), and the ESPP.

2 Excludes purchase rights under our ESPP for the purchase right period that commenced on January 1, 2024, and ended on December 15, 2024. Excludes 735,165 deferred, vested rights to receive shares pursuant to the Tetra Tech DCP.

3 Represents the weighted average exercise price of outstanding stock options only.

4 Consists of 8,826,925 shares available under the 2015 EIP, 12,811,285 shares available under the 2018 EIP, and 890,250 shares available under the ESPP. Shares available under the 2018 EIP can be used for any type of award available under that plan, including options, restricted stock, and RSU awards.

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Pay Ratio Disclosure

As required by Section 953(b) of the Dodd Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) and Item 402(u) of Regulation S K under the Securities Act, Tetra Tech is providing the following information about the relationship of the annual total compensation of our employees (excluding our CEO) and the annual total compensation of Mr. Batrack, our Chairman of the Board and CEO. The pay ratio was calculated in a manner consistent with Item 402(u) of Regulation S K and based upon our reasonable judgment and assumptions. For FY 2024, CEO compensation, which was earned but not realized, was $12,560,342; the median employee compensation (excluding our CEO) was $101,288; and our estimate of the CEO pay ratio was 124.

The regulation allows companies to identify the median employee every three years unless there has been a change in the employee population or compensation arrangements that would significantly change its CEO pay ratio disclosure. For FY 2024, Tetra Tech did not have a significant population change from the prior fiscal year. Therefore, we used the same data set for Tetra Tech’s global population as of July 1, 2023, to determine the median employee compensation.

Earnings figures for the 39-week period from October 1, 2022, through July 1, 2023, were collected. Non-U.S. dollar earnings were converted to U.S. dollars based on the exchange rate on July 1, 2023. Earnings were annualized for employees who worked a partial year because of a hire date that fell after the start of the fiscal year. Earnings were not annualized for casual employees.

This information is being provided for compliance purposes. Neither the Compensation Committee nor our management used the pay ratio measure in making compensation decisions. Given the different methodologies that companies use to determine an estimate of their pay ratio, the estimated ratio reported above should not be used as a basis for comparison between companies.

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Pay Versus Performance Disclosure

As required by Item 402(v) of Regulation S-K, we are providing the following information about the relationship between “compensation actually paid” to our CEO and to our other NEOs and certain financial performance of the Company. Compensation actually paid, as determined under SEC requirements, does not reflect the actual amount of compensation earned by or paid to our executive officers during a covered fiscal year. For further information concerning the Company’s pay-for-performance philosophy and how the Company aligns executive compensation with the Company’s performance, please refer to the Compensation Discussion and Analysis

Pay Versus Performance Table

					Value of Initial Fixed $100 Invested Based On:
Year1	SCT Total Compensation for CEO	Compensation Actually Paid to CEO2	Average SCT Total Compensation for Other NEOs	Average Compensation Actually Paid to Other NEOs3	Company TSR	Peer Group4	Net Income ($M)	Revenue5 ($M)
2024	$12,560,342	$24,898,843	$2,674,252	$4,579,192	$263.94	$203.12	$333.4	$5,198.7
2023	$11,885,517	$16,020,470	$2,595,666	$3,337,863	$169.64	$144.75	$273.4	$4,522.6
2022	$10,331,897	$9,306,681	$2,318,379	$2,065,988	$142.49	$109.24	$263.1	$3,504.0
2021	$7,908,335	$18,481,077	$2,109,249	$3,740,891	$167.37	$113.29	$232.8	$3,212.5

Notes:

1 The CEO and other NEOs for the indicated years were as follows: (i) for 2024, our PEO was Batrack and our other NEOs were Burdick, Shoemaker, Hopson, and Argus (ii) for 2023, our PEO was Batrack and our other NEOs were Burdick, Shoemaker, Hopson, and Argus, (iii) for 2022, our CEO was Batrack and our other NEOs were Burdick, Shoemaker, Amidon, and Hopson, (iv) and for 2021, our CEO was Batrack and our other NEOs were Burdick, Shoemaker, Argus, and Hopson.

2 Amounts reported in this column are based on total compensation reported for our CEO in the Summary Compensation Table for the indicated fiscal years and adjusted as shown in the tables below. Fair value of equity awards was computed in accordance with the Company’s methodology used for financial reporting purposes.

Fiscal Year	Summary Compensation Table Total	Adjustment to Summary Compensation Table Total1	Compensation Actually Paid
2024	$12,560,342	$12,338,501	$24,898,843
2023	$11,885,517	$4,134,953	$16,020,470
2022	$10,331,897	($1,025,216)	$9,306,681
2021	$7,908,335	$10,572,742	$18,481,077

1 See table below for calculation of Adjustment to Summary Compensation Table Total

Fiscal Year	Deduction of Grant Date Fair Value of Current Year Equity Awards	Addition of Fair Value of Current Year Equity Awards at FYE	Deduction for Awards Granted in Prior Years that Fail to Meet Vesting Criteria	Additions (Deductions) for Change in Value of Prior Years’ Awards Unvested at FYE	Additions (Deductions) for Change in Value of Prior Years’ Awards That Vested in Fiscal Year	Dollar Value of Dividends not Otherwise Reflected in the Fair Value for Covered Fiscal Year	Adjustment to Summary Compensation Table Total
2024	$(7,985,017)	$11,903,114	$0	$7,892,963	$479,919	$47,522	$12,338,501
2023	$(6,859,003)	$6,239,770	$0	$2,833,515	$1,853,143	$67,527	$4,134,953
2022	$(6,281,608)	$3,979,305	$0	$(1,831,074)	$3,024,666	$83,495	$(1,025,216)
2021	$(4,601,813)	$5,668,783	$0	$6,914,928	$2,516,496	$74,348	$10,572,742

3 Amounts reported in this column are based on the average of the total compensation reported for our other NEOs in the Summary Compensation Table for the indicated fiscal years and adjusted as shown in the tables below. Fair value of equity awards was computed in accordance with the Company’s methodology used for financial reporting purposes.

Fiscal Year	Average Summary Compensation Table Total	Adjustment to Average Summary Compensation Table Total1	Average Compensation Actually Paid
2024	$2,674,252	$1,904,939	$4,579,192
2023	$2,595,666	$742,198	$3,337,863
2022	$2,318,379	$(252,392)	$2,065,988
2021	$2,109,249	$1,631,643	$3,740,891

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Pay Versus Performance Disclosure

1 See table below for calculation of Adjustment to Average Summary Compensation Table Total

Fiscal Year	Deduction of Grant Date Fair Value of Current Year Equity Awards	Addition of Fair Value of Current Year Equity Awards at FYE	Additions (Deductions) for Change in Value of Prior Years’ Awards Unvested at FYE	Additions (Deductions) for Change in Value of Prior Years’ Awards That Vested in Fiscal Year	Dollar Value of Dividends not Otherwise Reflected in the Fair Value for Covered FY	Adjustment to Average Summary Compensation Table Total
2024	$(1,140,651)	$1,700,334	$1,247,331	$91,137	$6,789	$1,904,939
2023	$(1,028,804)	$935,927	$520,160	$303,504	$11,411	$742,198
2022	$(1,024,644)	$649,101	$(335,039)	$441,571	$16,620	$(252,392)
2021	$(934,781)	$1,151,515	$1,068,729	$333,464	$12,715	$1,631,643

4 For each indicated covered year, the peer group was composed of the following companies:

FY 2021: Booz Allen Hamilton Holding Co., CACI International, Dycom Industries, FTI Consulting, ICF International, KBR Inc., Leidos Holdings, ManTech International Corp., Parsons Corp., Science Applications International, Stantec Inc., and WSP Global

FY 2022: Booz Allen Hamilton Holding Co., CACI International, Dycom Industries, FTI Consulting, ICF International, KBR Inc., Leidos Holdings, Parsons Corp., Science Applications International, Stantec Inc., and WSP Global

FY 2023: Booz Allen Hamilton Holding Co., CACI International, Dycom Industries, FTI Consulting, ICF International, KBR Inc., Leidos Holdings, Parsons Corp., Science Applications International, Stantec Inc., and WSP Global

FY 2024: AECOM, Booz Allen Hamilton Holding Co., CACI International, Clarivate Plc, Dycom Industries, FTI Consulting, ICF International, KBR Inc., Leidos Holdings, Maximus Inc., Parsons Corp., Science Applications International, Stantec Inc., and Verisk Analytics

For 2024, AECOM, Clarivate Plc, Maximus Inc., and Verisk Analytics were added to the Peer Group. WSP Global was removed from the group. These changes were made to reflect the peers of the Company in light of changes to the Company’s size, in part due to the acquisition of RPS Group. Using the group from fiscal year 2023, the peer group TSR would be as follows: (i) 2024: $250.45; 2023: $173.28; 2022: $140.27; 2021: $124.91

5 In accordance with SEC rules, the Company is required to include in the Pay versus Performance table the “most important” financial performance measure (as determined by the Company) used to link compensation actually paid to our named executive officers to Company performance for the most recently completed fiscal year. The Company determined revenue, which is a metric included in our incentive program, meets this requirement and therefore, we have included this performance measure in the Pay versus Performance table.

Description of the Relationship Between Compensation Actually Paid to our Named Executive Officers and Company Performance

The charts below describe the relationship between compensation actually paid (CAP) to our chief executive officer and the average of the compensation actually paid to our other named executive officers (as calculated above) and our financial and stock performance for the indicated years. In addition, the first chart below compares our cumulative total shareholder return (TSR) and peer group cumulative TSR for the indicated years.

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[MISSING IMAGE: bc_capvsnetincome-pn.jpg]

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Company’s Most Important Financial Performance Measures

The following were the most important financial performance measures (and non-financial performance measures), as determined by the Company, that link compensation actually paid to our NEOs to the Company’s performance for the most recently completed fiscal year.

•

Revenue

•

Net Revenue

•

Operating Income

•

Earnings per Share

•

Cash Provided by Operations

All of the information provided above under the “Pay Versus Performance Disclosure” heading will not be deemed to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, whether made before or after the date hereof and irrespective of any general incorporation language in any such filing, except to the extent the Company specifically incorporates such information by reference.

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Item 3: Ratification of Appointment of Independent Registered Public Accounting Firm

The Audit Committee has appointed PwC as our independent registered public accounting firm for the 2025 fiscal year, and our Board is seeking stockholder ratification of the appointment. Stockholder ratification is not required by our bylaws or applicable laws and regulations. Our Board, however, annually submits the appointment for stockholder ratification as a matter of good corporate governance. If stockholders were not to ratify the appointment, the Audit Committee would reconsider whether to retain PwC, but could do so at the Audit Committee’s discretion. In addition, even if the appointment is ratified, the Audit Committee could subsequently appoint a different independent registered public accounting firm without stockholder approval if the Committee was to determine that action would be in the best interests of our company and stockholders.

PwC has been our independent registered public accounting firm since FY 2004 and served in that capacity for the 2024 fiscal year. PwC is knowledgeable about our operations and accounting practices and we believe that PwC is well qualified to act as our independent registered public accounting firm. Some governance stakeholders have suggested that a long-tenured auditor poses an independence risk. The Audit Committee, however, has several practices in place that mitigate this potential risk, including the following:

•

Review of all non-audit services and engagements provided by PwC in annually assessing PwC’s independence

•

Periodic consideration of whether to change the independent registered public accounting firm based on its assessment of PwC’s audit quality, performance, compensation, and independence

•

Regular meetings with PwC without management present and with management without PwC present

•

Involvement in the interview and selection process for any new lead audit partner

In order to regularly bring a fresh perspective to the audit engagement, a new lead audit partner is designated at least every five years. The Audit Committee Chair interviewed the partner prior to this designation, and the Audit Committee as a whole was directly involved with members of senior management and PwC in making the selection.

In determining whether to reappoint PwC, the Audit Committee considered the qualifications, performance, and independence of the firm and the audit engagement team; the quality of its discussion with PwC; and the fees charged by PwC for the level and quality of services provided. Although no formal statement from PwC is planned, representatives of the firm will be given the opportunity to make a statement if they so desire and will be present at the 2025 Annual Meeting to answer appropriate questions from stockholders.

Vote Required

Recommendation of Board of Directors

Our Board of Directors recommends that you vote FOR ratification of the appointment of PwC as Tetra Tech’s independent registered public accounting firm for the 2025 fiscal year. Properly dated and signed proxies will be so voted unless stockholders specify otherwise.

Auditor Independence

PwC has confirmed that it is in compliance with all rules, standards, and policies of the Public Company Accounting Oversight Board (PCAOB) and the regulations of the SEC governing auditor independence. The Audit Committee considers at least annually whether PwC’s provision of non-audit services is compatible with maintaining auditor independence.

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Item 3: Ratification of Appointment of Independent Registered Public Accounting Firm

Auditor Fees

The following is a summary of the fees PwC has billed Tetra Tech for professional services rendered for the fiscal years ended September 29, 2024, and October 1, 2023.

Fee Category	FY 2024 Fees	FY 2023 Fees
Audit Fees	$4,045,813	$4,619,243
Audit-Related Fees	89,074	130,000
Tax Fees	69,355	264,114
All Other Fees	2,000	4,150
Total Fees	$4,206,242	$5,017,508

Audit Fees

These fees are billed for professional services rendered for the integrated audit of our consolidated financial statements and our internal control over financial reporting, for the reviews of the interim consolidated financial statements included in our quarterly reports, and for services that are normally provided by PwC in connection with statutory and regulatory filings or other engagements.

Audit-Related Fees

These fees are billed for assurance and related services that were related to the performance of the audit or review of our financial statements and were not reported under “Audit Fees.” This category may include fees related to the performance of audits and attestation services not required by statute or regulations, due diligence activities related to acquisitions, and accounting consultations about the application of generally accepted accounting principles to proposed transactions.

Tax Fees

These fees are billed for professional services for tax compliance, tax advice, tax planning, and tax returns. These services include assistance regarding federal, state, and international tax compliance; assistance with tax reporting requirements, tax returns, and audit compliance; M&A tax compliance; and tax advice on international and state tax matters. None of these services was provided under contingent fee arrangements.

All Other Fees

These fees are associated with annual license fees for software used by management in performing technical research and ensuring completeness of financial statement disclosures.

Policy on Audit Committee Pre-Approval of Audit and Permissible Non-Audit Services

The Audit Committee’s policy is to pre-approve all audit and permissible non audit services to be provided by the independent registered public accounting firm, subject to limited discretionary authority granted to our executive management. These services may include audit services, audit related services, tax services, and other services. Pre-approval is detailed as to the particular service or category of services. The independent registered public accounting firm and management are required to periodically report to the Audit Committee on the extent of services provided by the independent registered public accounting firm in accordance with this pre-approval and the fees for the services performed to date. The Audit Committee may also pre-approve specific services on a case-by-case basis. The Audit Committee pre-approved all audit and permissible non audit services provided by PwC in FY 2023 and FY 2024 in accordance with this policy.

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Audit Committee Report

Management is responsible for the Company’s internal controls and the financial reporting process. The Company’s independent registered public accounting firm is responsible for performing an independent audit of the Company’s consolidated financial statements and internal controls over financial reporting in accordance with the standards of the PCAOB and to issue a report thereon. The Audit Committee’s responsibility is to monitor and oversee these processes, but the Committee is not responsible for preparing the Company’s financial statements or auditing those financial statements, which are the responsibilities of management and the independent auditors, respectively.

The Audit Committee has reviewed with PwC the matters required to be discussed with the Committee under the applicable requirements of the PCAOB and the SEC. The Audit Committee has also discussed with the Company’s management auditors and PwC the overall scope and plan for their respective audits. The Audit Committee meets regularly with the management auditors and independent auditors to discuss the results of their examinations, their evaluations of the Company’s internal controls, and the overall quality of the Company’s financial reporting.

The Audit Committee has reviewed and discussed with management the audited financial statements of the Company for the fiscal year ended September 29, 2024. In connection with that review, management represented to the Audit Committee that the Company’s consolidated financial statements were prepared in accordance with generally accepted accounting principles. The Audit Committee has also reviewed management’s report on its assessment of internal controls over financial reporting, as required under the Sarbanes Oxley Act of 2002. In its report, management provided a positive assertion that internal controls over financial reporting were in place and operating effectively as of September 29, 2024.

The Audit Committee has discussed with PwC the consolidated financial statements as well as the matters required to be discussed pursuant to Auditing Standard 1301, Communications with Audit Committees. The Audit Committee has also received a letter from PwC regarding its independence from the Company as required by PCAOB Ethics and Independence Rule 3526, Communication with Audit Committees Concerning Independence, has discussed with PwC the independence of the firm, and has considered all of the above communications as well as all audit, audit related, and non-audit services provided by PwC. With reliance upon the foregoing, the Audit Committee has determined that PwC is an independent registered public accounting firm with respect to the Company within the meaning of the Securities Act and the regulations thereunder adopted by the SEC and the PCAOB.

Based on the reviews and discussions detailed above, the Audit Committee recommended to the Board of Directors that the audited financial statements be included in the Company’s Annual Report on Form 10-K for FYE September 29, 2024, as filed with the SEC.

Respectfully submitted by:

Gary R. Birkenbeuel, Chair
Kimberly E. Ritrievi
Kirsten M. Volpi

This Audit Committee Report does not constitute soliciting material and should not be deemed filed or incorporated by reference into any of our filings under the Securities Act or the Exchange Act, whether made before or after the date of this proxy statement, unless specifically incorporated by reference herein.

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Security Ownership Information

Security Ownership of Management and Significant Stockholders

The following table sets forth information known to Tetra Tech with respect to beneficial ownership of our common stock at January 2, 2025, by:

•

All those persons known by us to own beneficially more than 5% of our common stock

•

Each director and director nominee

•

Our NEOs

•

All directors and executive officers as a group

Beneficial ownership is determined under the rules of the SEC and generally includes voting or investment power with respect to securities. To our knowledge, except as indicated in the footnotes to this table and pursuant to applicable community property laws, the persons named in the table have sole voting and investment power with respect to all shares of common stock beneficially owned. The number of shares beneficially owned by each person or group as of January 2, 2025, includes shares of common stock that such person or group had the right to acquire on or within 60 days after January 2, 2025, including, but not limited to, upon the exercise of options. References to options in the footnotes of the table include only options to purchase shares exercisable on or within 60 days after January 2, 2025. Unless otherwise indicated, percentage ownership is calculated by dividing the number of shares beneficially owned by such person or group by the sum of (1) the 268,028,347 shares of common stock outstanding on January 2, 2025, and (2) any shares such person or group has the right to acquire on or within 60 days after January 2, 2025.

Beneficial Ownership of Common Stock

Name of Beneficial Owner1	Shares Beneficially Owned (#)	Percentage Owned
BlackRock, Inc.2	27,702,880	10.4
The Vanguard Group, Inc.3	25,769,265	9.7
Pictet Asset Management SA 4	13,637,450	5.1
AllianceBernstein L.P.5	13,188,670	5.0
Mr. Argus	25,841	*
Mr. Batrack	225,867	*
Mr. Birkenbeuel	40,115	*
Mr. Burdick	131,115	*
Mr. Douglas	—	—
Mr. Gandhi	10,731	*
Mr. Hopson	63,931	*
Ms. Obiaya	3,810	*
Dr. Ritrievi	145,590	*
Dr. Shoemaker	307,990	*
Ms. Volpi6	86,312	*
All directors and executive officers as a group (11 persons)	1,074,526	*

* Less than 1%.

1 Unless otherwise indicated, the address of each person in this table is c/o Tetra Tech, 3475 E. Foothill Boulevard, Pasadena, California 91107, Attention: Corporate Secretary. Ownership information reported here does not include shares held by officers or directors in the DCP.

2 All information regarding share ownership is taken from and furnished in reliance upon the Schedule 13G (Amendment No. 12), as of December 31, 2023, filed by BlackRock, Inc. with the SEC on January 24, 2024, whose address is 55 East 52nd Street, New York, New York 10055. According to the Schedule 13G/A, BlackRock, Inc. has sole voting power over 26,689,670 shares of our common stock and sole dispositive power over 27,702,380 shares of our common stock.

3 All information regarding share ownership is taken from and furnished in reliance upon the Schedule 13G (Amendment No. 12), as of December 29, 2023, filed by The Vanguard Group, Inc. (Vanguard) with the SEC on February 13, 2024, whose address is 100 Vanguard Boulevard, Malvern, Pennsylvania 19355. According to the Schedule 13G/A, Vanguard has shared voting power over 95,940 shares of our common stock, sole dispositive power over 25,421,405 shares of our common stock, and shared dispositive power over 347,860 shares of our common stock.

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4 All information regarding share ownership is taken from and furnished in reliance upon the Schedule 13G, as of September 30, 2024, filed by Pictet Asset Management SA. (Pictet) with the SEC on November 21, 2024, whose address is 60 Route de Acacias, 1211 Geneva 73, Switzerland. According to the Schedule 13G, Pictet has sole voting power over 13,637,450 shares of our common stock and sole dispositive power over 13,637,450 shares of our common stock.

5 All information regarding share ownership is taken from and furnished in reliance upon the Schedule 13G, as of December 31, 2023, filed by AllianceBernstein L.P. with the SEC on February 14, 2024, whose address is 1345 Avenue of the Americas, New York, NY 10105. According to the Schedule 13G, AllianceBernstein has sole voting power over 9,595,860shares of our common stock, sole dispositive power over 12,898,840 shares of our common stock and shared dispositive power over 289,830 shares of our common stock.

6 Includes options to purchase 16,000 shares that are exercisable on or within 60 days after January 2, 2025.

Section 16(a) Beneficial Ownership Reporting Compliance

Section 16(a) of the Exchange Act requires our executive officers, directors, and owners of more than 10% of our equity securities (collectively, our insiders) to timely file initial reports of ownership and reports of changes in ownership with the SEC. Due to the complexity of SEC reporting rules, we undertake to file these reports on behalf of our directors and executive officers and have instituted procedures to assist them with complying with their reporting obligations. To our knowledge, based solely on our review of SEC filings, our records, and written representations from certain of our insiders that no other reports were required to have been filed, we believe that all our insiders timely complied with the Section 16(a) filing requirements applicable to them during FY 2024.

Related Person Transactions

Our Board of Directors has adopted a written related person transactions policy. Under the policy, the Audit Committee (or other committee designated by the NCG Committee) reviews transactions between Tetra Tech and related persons, including to identify, review, approve and disclose, if necessary, any transaction, arrangement or relationship (or any series of similar transactions, arrangements or relationships) in which (i) we (including any of our subsidiaries) was, is or will be a participant; (ii) the amount involved exceeds $120,000; and (iii) a related person had, has or will have a direct or indirect material interest (a “Related Person Transaction”). For purposes of the policy, a “related person” is a director, executive officer, nominee for director, or beneficial owner of more than 5% of our common stock, in each case, since the beginning of the last fiscal year, and their immediate family members.

Related Person Transactions that do not fall into certain pre-approved categories in accordance with Item 404 of Regulation S-K promulgated under the Exchange Act must be reviewed by our Disclosure Committee, which consists of an internal team of senior representatives from our finance, accounting, legal, human resources, tax, treasury, investor relations, and information technology departments. The Disclosure Committee determines whether a related person could have a significant interest in the transaction, and, if so, the transaction is referred to the Audit Committee (or other designated committee). Transactions also may be identified through our Code of Business Conduct, our quarterly certification process, or our other policies and procedures and reported to the Audit Committee (or other designated committee). The Audit Committee will review the material facts of all Related Person Transactions and either approve, ratify, rescind, or take other appropriate action (in its discretion) with respect to the transaction.

Tetra Tech had no Related Person Transactions in FY 2024.

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Meeting and Voting Information

This proxy statement is being furnished to stockholders on behalf of our Board to solicit proxies for the 2025 Annual Meeting to be held on Thursday, February 27, 2025, at 10:00 a.m. Pacific Time, at the Le Méridien Pasadena Arcadia, 130 West Huntington Drive, Arcadia, California 91007, and at any adjournment or postponement thereof. The items of business to be acted upon at the meeting are set forth in the Notice of 2025 Annual Meeting of Stockholders (“Notice”) appearing at the beginning of this proxy statement.

Delivery of Annual Report on Form 10-K

We will mail without charge, upon written request, a copy of our Annual Report on Form 10-K for FYE September 29, 2024, including the consolidated financial statements, schedules and list of exhibits, and any particular exhibit specifically requested. Requests should be sent to our Corporate Secretary, Tetra Tech, 3475 E. Foothill Boulevard, Pasadena, California 91107. Our Annual Report on Form 10-K is also available at tetratech.com.

Delivery of Proxy Materials

We have elected to provide access to our proxy materials on the internet. Accordingly, we are sending the Notice to our stockholders of record. Brokers, banks, and other nominees (collectively, nominees) who hold shares on behalf of the beneficial owners (also called “street name holders”) will send a similar notice to beneficial owners. All stockholders will have the ability to access our proxy materials on the website referred to in the Notice or to request a printed copy of the proxy materials. Instructions on how to request printed proxy materials by mail, including an option to receive paper copies in the future, are provided in the Notice and on the website referred to in the Notice.

We intend to mail this proxy statement, together with a proxy card, to stockholders entitled to vote at the 2025 Annual Meeting who properly request paper copies of these materials within three business days of request. If you hold your shares in street name, you may request paper copies of the proxy statement and proxy card from your nominee by following the instructions on the notice your nominee provides to you.

Householding

We have adopted a procedure approved by the SEC called “householding.” Under this procedure, we are permitted to deliver a single copy of our proxy materials, including this proxy statement and our Annual Report, to stockholders sharing the same address who did not receive the Notice and who did not otherwise notify us of their desire to receive multiple copies of our proxy materials. Householding allows us to reduce our printing and postage costs and limits the volume of duplicative information received at your household. Householding affects only the delivery of proxy materials; it has no impact on the delivery of dividend checks.

We will promptly deliver, upon oral or written request, a separate copy of the proxy materials to any stockholder residing at an address to which only one copy was mailed. If you wish to receive an additional copy of our proxy materials, or if you received multiple copies of our proxy materials and wish to request householding in the future, you may make such request by writing to our Corporate Secretary at Tetra Tech, 3475 E. Foothill Boulevard, Pasadena, California 91107.

If you are a street name holder and wish to revoke your consent to householding and receive separate copies of our proxy materials in future years, you may call Broadridge Investor Communications Solutions, Inc. toll-free at (800) 542-1061 or write to them c/o Householding Department, 51 Mercedes Way, Edgewood, New York 11717.

Shares Entitled to Vote

Stockholders of record as of the close of business on January 2, 2025, are entitled to notice of, and to vote at, the 2025 Annual Meeting. Our only class of shares outstanding is common stock, and there were 268,028,347 shares of our common stock outstanding on January 2, 2025. Pursuant to our bylaws, a list of stockholders entitled to vote will be available for inspection at least 10 days before the 2025 Annual Meeting and at the 2025 Annual Meeting. Each stockholder of record is entitled to one vote for each share of common stock held on the record date.

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Meeting and Voting Information

Voting Your Shares

Voting in Person

You may vote by attending the 2025 Annual Meeting and voting in person or you may vote by submitting a proxy. If you hold your shares in street name, you may vote in person at the meeting only if you properly request and receive a legal proxy in your name from the nominee that holds your shares. See Shares Registered in Street Name below.

If you hold your shares of common stock as a record holder (i.e., directly in your name), your method of voting differs depending on whether you are viewing this proxy statement on the internet or reviewing a paper copy, as follows:

•

If you received a notice of internet availability or an email, you may vote your shares by (1) submitting a proxy on the internet by following the instructions on the website or (2) requesting a paper copy of the proxy materials and following one of the methods described below.

•

If you received a paper proxy card or voting instruction card, you may vote your shares by (1) submitting a proxy by telephone or on the internet by following the instructions on the proxy card or (2) completing, dating, and signing the proxy card included with the proxy statement and returning it in the pre-addressed, postage-paid envelope provided.

We encourage you to vote by telephone or on the internet since those methods immediately record your vote and allow you to confirm that your vote has been properly recorded. If you vote by internet or telephone, then you need not return a written proxy card by mail.

Shares Registered in Street Name

If you hold your shares of common stock in street name, which means your shares are held of record by a nominee, you will receive instructions from your nominee on how to vote your shares. Your nominee will allow you to deliver your voting instructions over the internet and might also permit you to vote by telephone. In addition, if you received a printed copy of this proxy statement, you may submit your voting instructions by completing, dating, and signing the voting instruction form included with the proxy statement and promptly returning it in the pre-addressed, postage-paid envelope provided. If you vote by internet or telephone, then you need not return a written voting instruction form by mail.

Manner of Voting in the Absence of Instructions

In the event that you return a signed and valid proxy card on which no directions are specified, your shares will be voted in the following manner:

•

FOR the election of the seven directors nominated by our Board to serve one-year terms until the 2026 Annual Meeting, and until their respective successors are duly elected and qualified or until his or her resignation or removal.

•

FOR the approval, on an advisory basis, of our named executive officers’ compensation.

•

FOR the ratification of the appointment of PwC as our independent registered public accounting firm for FY 2025.

•

In the discretion of the proxy holders as to any other matters that may properly come before the 2025 Annual Meeting or any postponement or adjournment of the 2025 Annual Meeting.

Deadline for Voting By Proxy

If you are a stockholder of record, your proxy must be received by telephone or via the internet by 11:59 p.m. Eastern Time on February 26, 2025, for your shares to be voted at the 2025 Annual Meeting. If you are a stockholder of record and you received a printed set of proxy materials, you also have the option of completing, signing, dating, and returning the proxy card enclosed with the proxy materials before the 2025 Annual Meeting for your shares to be voted at the meeting. If you hold your shares of common stock in street name, please comply with the deadlines included in the voting instructions provided by the nominee that holds your shares.

Revoking Your Proxy or Changing Your Vote

A stockholder giving a proxy pursuant to this solicitation may revoke it at any time before it is acted upon at the 2025 Annual Meeting by (1) submitting another proxy by telephone or on the internet (only your last voting instructions will be counted); (2) sending a later dated paper proxy; (3) delivering to our Corporate Secretary a written notice of revocation prior to the voting of the proxy

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at the 2025 Annual Meeting; or (4) voting in person at the 2025 Annual Meeting. Simply attending the 2025 Annual Meeting will not revoke your proxy. Any change to your proxy provided by telephone or via the internet must be submitted by 11:59 p.m. Eastern Time on February 26, 2025.

If your shares are held in street name, you may change your vote by submitting new voting instructions to your nominee. You must contact your nominee to find out how you can change your vote.

Quorum and Votes Required

Votes cast by proxy or in person at the 2025 Annual Meeting will be tabulated by Broadridge Financial Solutions, Inc., the independent agent appointed as inspector of election by our Board. The inspector of election will also determine whether a quorum is present.

At the 2025 Annual Meeting, the existence of a quorum and tabulation of votes is determined as follows:

•

The presence in person or representation by proxy of a majority of the outstanding shares of common stock on the record date and entitled to vote at the 2025 Annual Meeting shall constitute a quorum for the transaction of business. Shares represented by proxies that reflect abstentions or “broker nonvotes” (which are shares held by a nominee that are represented and voted on a routine matter at the meeting, but with respect to which the nominee is not empowered to vote on another nonroutine matter at the meeting) will be counted as shares that are present and entitled to vote at the 2025 Annual Meeting for purposes of determining the presence of a quorum. The items scheduled to be considered at the 2025 Annual Meeting all are “nonroutine” under the applicable rules, except for Item 3, ratification of appointment of our independent registered public accounting firm. Nominees are prohibited from voting on nonroutine items in the absence of instructions from the beneficial owners of the shares. As a result, if you hold your shares in street name and do not submit voting instructions to your nominee, your shares will be voted on Item 3 in the manner directed by your nominee, but will not be voted on Item 1, election of directors or Item 2, advisory vote to approve our named executive officers’ compensation, and will constitute broker nonvotes on each such item. We urge you to promptly provide voting instructions to your nominee so that your vote is counted for Item 1 and Item 2.

•

Because there is no cumulative voting and this is an uncontested election, each of the director nominees named in Item 1 receiving a majority of the votes cast will be elected as a director (for these purposes, “a majority of votes cast” means that the number of shares voted “for” a director’s election exceeds the number of shares voted “against” that director’s election). Abstentions and broker nonvotes will not count as a vote cast for or against a nominee’s election and, therefore, will have no effect in determining whether a director nominee has received a majority of the votes cast.

•

For Item 2, advisory vote to approve our named executive officers’ compensation, and Item 3, ratification of appointment of our independent registered public accounting firm, the affirmative vote of the majority of the shares represented at the 2025 Annual Meeting and entitled to vote on the item will be the act of the stockholders. Abstentions as to a particular item will have the same effect as a vote against that item. Broker nonvotes will have no effect on the vote for Item 2. Ratifying the appointment of our independent registered public accounting firm is considered a routine matter on which brokers may vote in their discretion on behalf of beneficial owners. Accordingly, broker nonvotes should not be applicable to Item 3. Also, Item 2 and Item 3 are advisory only and are not binding on our Company. Our Board of Directors will consider the outcome of the vote on each of these items in considering what action, if any, should be taken in response to the advisory vote by stockholders.

Vote Results

We intend to announce preliminary voting results at the conclusion of the 2025 Annual Meeting. We expect to report final voting results in a Current Report on Form 8-K filed with the SEC on or before four business days following the 2025 Annual Meeting.

Proxy Solicitation

Tetra Tech will bear all costs related to this solicitation of proxies. Some of our employees may solicit proxies in person, by telephone, or by email; those employees will not receive any additional compensation for their proxy solicitation efforts. We will reimburse banks, brokers, and other custodians, nominees, and fiduciaries for reasonable out of pocket expenses they incur in forwarding our proxy materials to beneficial stockholders. You can help reduce these costs by electing to access proxy materials electronically.

Electronic Access to Proxy Materials and Annual Report

Instead of receiving paper copies of proxy statements and annual reports by mail in the future, you can elect to receive an email message that will provide a link to those documents on the internet. By opting to access proxy materials via the internet, you will be

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able to access them more quickly, save us the cost of printing and mailing them to you, reduce the amount of mail you receive from us, and help us preserve environmental resources.

You may enroll to access proxy materials and annual reports electronically for future Annual Meetings by registering online at the following website: proxyvote.com. If you vote on the internet, simply follow the prompts on the voting website to link to the electronic enrollment website.

Annual Meeting Procedures

You are entitled to attend the 2025 Annual Meeting if you were a stockholder of record or a beneficial owner of our common stock on January 2, 2025, or you hold a valid legal proxy for the 2025 Annual Meeting. If you are a stockholder of record, you may be asked to present valid picture identification, such as a driver’s license or passport, for admission to the 2025 Annual Meeting.

If your shares are registered in the name of a nominee, you may be asked to provide proof of beneficial ownership as of January 2, 2025, such as a brokerage account statement, a copy of the Notice or voting instruction form provided by your nominee, or other similar evidence of ownership as well as picture identification for admission. If you wish to be able to vote in person at the 2025 Annual Meeting, you must obtain a legal proxy from your nominee and present it to the inspector of election with your ballot.

Submission of Stockholder Items for 2026 Annual Meeting

Requirements for Stockholder Proposals to be Considered for Inclusion in Our Proxy Materials

Our stockholders may submit proposals on matters appropriate for stockholder action at meetings of our stockholders in accordance with Rule 14a-8 promulgated under the Exchange Act. For proposals to be included in our proxy materials for our 2026 Annual Meeting, all applicable requirements of Rule 14a-8 must be satisfied and the proposals must be received no later than September 18, 2025. If we change the date of the 2026 Annual Meeting by more than 30 days from the anniversary of this year’s meeting, stockholder proposals must be received a reasonable time before we begin to print and mail our proxy materials for the 2026 Annual Meeting. Proposals should be delivered to the Corporate Secretary, Tetra Tech, 3475 E. Foothill Boulevard, Pasadena, California 91107.

Requirements for Nomination of Director Candidates for Inclusion in our Proxy Materials

Our bylaws provide that if a stockholder or group of up to 20 stockholders that has continuously owned for three years at least 3% of our outstanding common stock wishes to nominate and include in our proxy materials director candidates constituting up to the greater of two individuals or 20% of our Board through our proxy access provision, stockholders must provide proper written notice of the nomination on or between August 19, 2025 and September 18, 2025, subject to the additional requirements in our bylaws. Stockholder(s) and nominee(s) must satisfy the requirements specified in the bylaws and the proxy access nomination notice must contain the information required by the bylaws. If we change the date of the 2026 Annual Meeting by more than 30 days from the anniversary of the 2025 Annual Meeting, the stockholder’s notice must be delivered no earlier than the close of business on the 120th day prior to the 2026 Annual Meeting and no later than the close of business on the later of the 90th day prior to the 2026 Annual Meeting or the 10th day following the date on which public announcement of the meeting date is first made by the Company.

Requirements for Stockholder Proposals and Nomination of Director Candidates Not Intended for Inclusion in Our Proxy Materials

Our bylaws provide that stockholders seeking to present a proposal or nominate a director for election to our Board at the 2026 Annual Meeting but not intending for the proposal to be included in the proxy statement for that Annual Meeting must have given timely notice thereof in writing to the Corporate Secretary of Tetra Tech not later than the close of business on the 90th day nor earlier than the close of business on the 120th day prior to the first anniversary of the preceding year’s Annual Meeting. To be timely for the 2026 Annual Meeting, a stockholder’s notice must be delivered to or mailed and received by the Corporate Secretary at our principal executive offices on or between October 30, 2025, and November 29, 2025. In the event that the Annual Meeting is called for a date that is not within 30 days of the anniversary of the date on which the immediately preceding Annual Meeting of stockholders was held, however, to be timely, notice by the stockholder must be delivered not earlier than the close of business on the 120th day prior to that Annual Meeting nor later than the close of business on the later of the 90th day prior to such Annual Meeting or the 10th day following the date on which the date of the Annual Meeting is first publicly announced. The public announcement of an adjournment of an Annual Meeting of stockholders will not commence a new time period for the stockholder giving notice as provided above. A stockholder’s notice to the Corporate Secretary must provide the information required by our bylaws on each

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matter the stockholder proposes to bring before the Annual Meeting. In addition, a stockholder who intends to solicit proxies in support of director nominees other than the Company’s nominees at the 2026 Annual Meeting must deliver written notice to the Company setting forth the information required by Rule 14a-19 under the Exchange Act. If a stockholder’s written notice is not received between the dates specified above and does not satisfy these additional informational requirements, the notice will not be considered properly submitted and will not be acted upon at the 2026 Annual Meeting.

Pursuant to our bylaws, the chairman of the Annual Meeting will have the power and duty to determine whether a nomination or any business proposed to be brought before the Annual Meeting was made, or proposed, in accordance with the bylaws. Any proposed nomination or business that does not fully comply with the notice requirements of our bylaws will be disregarded and will not be brought before the 2026 Annual Meeting.

Other Matters

Our Board of Directors knows of no other matters to be presented for stockholder action at the 2025 Annual Meeting. If other matters properly come before the meeting or any adjournments or postponements thereof, however, the proxy holders named in the proxies solicited by the Board will have the authority to vote all proxies received with respect to such matters in their discretion, and it is their intention to vote such proxies in accordance with the recommendation of the Board.

By order of the Board of Directors,

Preston Hopson
Secretary
Pasadena, California
January 2025

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TETRA TECH, INC. C/O COMPUTERSHARE P.O. BOX 43070 PROVIDENCE, RI 02940-3070 SCAN TO VIEW MATERIALS & VOTE VOTE BY INTERNET - www.proxyvote.com or scan the QR Barcode above Use the Internet to transmit your voting instructions and for electronic delivery of information. Vote by 11:59 P.M. ET on 02/26/2025. Have your proxy card in hand when you access the web site and follow the instructions to obtain your records and to create an electronic voting instruction form. VOTE BY PHONE - 1-800-690-6903 Use any touch-tone telephone to transmit your voting instructions. Vote by 11:59 P.M. ET on 02/26/2025. Have your proxy card in hand when you call and then follow the instructions. VOTE BY MAIL Mark, sign and date your proxy card and return it in the postage-paid envelope we have provided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717. TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS: KEEP THIS PORTION FOR YOUR RECORDS DETACH AND RETURN THIS PORTION ONLY THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. The Board of Directors recommends you vote FOR the following: 1. Election of Directors Nominees For Against Abstain 1A Dan L. Batrack 1B Gary R. Birkenbeuel 1C John M. Douglas 1D Prashant Gandhi 1E Christiana Obiaya 1F Kimberly E. Ritrievi 1G Kirsten M. Volpi The Board of Directors recommends you vote FOR proposals 2 and 3. 2 To approve, on an advisory basis, the Company's named executive officers' compensation. 3 To ratify the appointment of PricewaterhouseCoopers LLP as the Company's independent registered public accounting firm for fiscal year 2025. NOTE: In their discretion, the proxies are authorized to vote on such other business as may properly come before the meeting or any postponement or adjournment thereof. Please sign exactly as your name(s) appear(s) hereon. All joint holders must sign. If signing as attorney, executor, administrator, or other fiduciary, please include full title. If a corporation or partnership, please include full corporate or partnership name and name of authorized officer signing. Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) Date 0000655452_1 R1.0.0.2

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Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting: The Notice & Proxy Statement, Annual Report, Shareholder Letter are available at www.proxyvote.com TETRA TECH, INC. Annual Meeting of Stockholders February 27, 2025 10:00 AM This proxy is solicited by the Board of Directors The stockholder(s) hereby revoke(s) all prior proxies to vote at the Annual Meeting or any postponement or adjournment thereof and appoint(s) Dan L. Batrack and Preston Hopson, and each of them, as proxies, each with full power of substitution, and hereby authorize(s) each of them to represent and to vote, as designated on the reverse side of this ballot and any other matters which may properly come before the Annual Meeting and all postponements or adjournments of the Annual Meeting, all of the shares of common stock of TETRA TECH, INC. that the stockholder(s) is/are entitled to vote at the Annual Meeting to be held at 10:00 AM Pacific Time on 02/27/2025, at Le Meridien Pasadena Arcadia, 130 West Huntington Drive, Arcadia, CA 91007, and any postponement or adjournment thereof. This proxy, when properly executed, will be voted in the manner directed herein or, if no such direction is made, this proxy will be voted in accordance with the Board of Directors' recommendations with respect to the election of directors and proposals 2 and 3, and in the discretion of the proxy holder(s) as to any other matters that may properly come before the Annual Meeting or any postponement or adjournment of the Annual Meeting. PLEASE MARK, SIGN, DATE AND RETURN THIS PROXY CARD PROMPTLY USING THE ENCLOSED POSTAGE-PAID ENVELOPE. IF YOU CHOOSE TO VOTE BY TELEPHONE OR INTERNET, DO NOT RETUN THIS PROXY. Continued and to be signed on reverse side 0000655452_2 R1.0.0.2