ThZeal - The Zeal

PIMCO Inflation Response Multi-Asset Fund

Summary Prospectus

August 1, 2024 (as supplemented June 2, 2025)

Share Class:	Inst	I-2	I-3	Admin	A
Ticker:	PIRMX	PPRMX	PFRMX	-	PZRMX

Before you invest, you may want to review the Fund’s prospectus, which, as supplemented, contains more information about the Fund and its risks. You can find the Fund’s prospectus, reports to shareholders (once available) and other information about the Fund online at http://investments.pimco.com/prospectuses. You can also get this information at no cost by calling 888.87.PIMCO or by sending an email request to piprocess@dstsystems.com. The Fund’s prospectus and Statement of Additional Information, both dated August 1, 2024, as supplemented, are incorporated by reference into this Summary Prospectus.

Investment Objective

The Fund seeks total return which exceeds that of its benchmark.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and example below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in Class A shares of eligible funds offered by PIMCO Equity Series and PIMCO Funds. More information about these and other discounts is available in the “Classes of Shares” section on page 59 of the Fund’s prospectus, Appendix B to the Fund’s prospectus (Financial Firm-Specific Sales Charge Waivers and Discounts) or from your financial professional.

Shareholder Fees (fees paid directly from your investment):

	Inst Class	I-2	I-3	Admin Class	Class A
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None	None	None	5.50%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original purchase price or redemption price)	None	None	None	None	1.00%

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

	Inst Class	I-2	I-3	Admin Class	Class A
Management Fees	0.69%	0.79%	0.89%	0.69%	0.89%
Distribution and/or Service (12b-1) Fees	N/A	N/A	N/A	0.25%	0.25%
Other Expenses(1)	1.24%	1.24%	1.24%	1.24%	1.24%
Acquired Fund Fees and Expenses(2)	0.24%	0.24%	0.24%	0.24%	0.24%
Total Annual Fund Operating Expenses	2.17%	2.27%	2.37%	2.42%	2.62%
Fee Waiver and/or Expense Reimbursement(3)(4)(5)	(0.22%)	(0.22%)	(0.27%)	(0.22%)	(0.22%)
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement(6)	1.95%	2.05%	2.10%	2.20%	2.40%

“Other Expenses” and Acquired Fund Fees and Expenses include interest expense of the Fund and of the Underlying PIMCO Funds of 1.24% and 0.02%, respectively.

Interest expense is borne by the Fund and the Underlying PIMCO Funds separately from the management fees paid to PIMCO. Excluding interest expense of the Fund and of the Underlying PIMCO Funds, Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement are 0.69%, 0.79%, 0.84%, 0.94% and 1.14% for Institutional Class, I-2, I-3, Administrative Class and Class A shares, respectively. Interest expense is calculated and presented equally across all share classes. As a result, Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement may not match the Ratio of Expenses to Average Net Assets for certain share classes, as set forth in the Financial Highlights table of the Fund’s prospectus, because the Ratio of Expenses to Average Net Assets is calculated based on the average net assets of the applicable share class.

Acquired Fund Fees and Expenses include the advisory fee and the supervisory and administrative fee paid by PIMCO Cayman Commodity Fund VII Ltd (the “Subsidiary”).

PIMCO has contractually agreed, through July 31, 2025, to waive, first, the advisory fee and, second, the supervisory and administrative fee it receives from the Fund in an amount equal to the expenses attributable to the Management Fees of Underlying PIMCO Funds indirectly incurred by the Fund in connection with its investments in Underlying PIMCO Funds, up to a maximum waived amount that is equal to the Fund's aggregate advisory fee and supervisory and administrative fee. This waiver renews annually for a full year unless terminated by PIMCO upon at least 30 days’ notice prior to the end of the contract term.

PIMCO has contractually agreed to waive the Fund’s advisory fee and the supervisory and administrative fee in an amount equal to the management fee and administrative services fee, respectively, paid by the Subsidiary to PIMCO. The Subsidiary pays PIMCO a management fee and an administrative services fee at the annual rates of 0.49% and 0.20%, respectively, of its net assets. This waiver may not be terminated by PIMCO and will remain in effect for as long as PIMCO’s contract with the Subsidiary is in place.

PIMCO has contractually agreed, through July 31, 2025, to reduce its supervisory and administrative fee for the Fund’s I-3 shares by 0.05% of the average daily net assets attributable to I-3 shares of the Fund. This Fee Waiver Agreement renews annually unless terminated by PIMCO upon at least 30 days’ prior notice to the end of the contract term.

Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement do not match the Ratio of Expenses to Average Net Assets of the Fund, as set forth in the Financial Highlights table of the Fund’s prospectus, because the Ratio of Expenses to Average Net Assets reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

Example. The Example is intended to help you compare the cost of investing in Institutional Class, I-2, I-3, Administrative Class or Class A shares of the Fund with the costs of investing in other mutual funds. The Example assumes that you invest $10,000 in the noted class of shares for the time periods indicated, and then hold or redeem all your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

If you redeem your shares at the end of each period:

	1 Year	3 Years	5 Years	10 Years
Institutional Class	$198	$658	$1,144	$2,486
I-2	$208	$688	$1,195	$2,588
I-3	$213	$714	$1,241	$2,686
Administrative Class	$223	$734	$1,271	$2,740
Class A	$780	$1,300	$1,845	$3,326

If you do not redeem your shares:

	1 Year	3 Years	5 Years	10 Years
Class A	$780	$1,300	$1,845	$3,326

PIMCO Funds | Summary Prospectus

PIMCO Inflation Response Multi-Asset Fund

Portfolio Turnover

The Fund pays transaction costs when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the Annual Fund Operating Expenses or in the Example tables, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 219% of the average value of its portfolio.

Principal Investment Strategies

The Fund is intended for investors who prefer to have their asset allocation decisions made by professional investment managers. PIMCO uses a three-step approach in seeking to achieve the Fund’s investment objective which consists of 1) developing a target asset allocation; 2) developing a series of relative value strategies designed to add value beyond the target allocation; and 3) utilizing hedging techniques to manage risks. PIMCO evaluates these three steps and uses varying combinations of Acquired Funds (defined below) and/or direct investments to implement them within the Fund.

The Fund may invest in Institutional Class or Class M shares of any funds of the Trust and PIMCO Equity Series, an affiliated open-end investment company, except other funds of funds and PIMCO California Municipal Intermediate Value Fund, PIMCO California Municipal Opportunistic Value Fund, PIMCO National Municipal Intermediate Value Fund and PIMCO National Municipal Opportunistic Value Fund (“Underlying PIMCO Funds”), and may also invest in other affiliated funds, including funds of PIMCO ETF Trust, and unaffiliated funds (collectively, “Acquired Funds”). The term “fund of funds” refers to mutual funds that pursue their investment objective by investing all or a significant portion of their assets in other funds.

The Fund seeks to achieve its investment objective by investing under normal circumstances in a combination of Fixed Income Instruments of varying maturities, equity securities, affiliated and unaffiliated investment companies, which may or may not be registered under the Investment Company Act of 1940, as amended (the “1940 Act”), forwards and derivatives, such as options, futures contracts or swap agreements, of various asset classes in seeking to mitigate the negative effects of inflation. Such asset classes include, but are not limited to, inflation-linked bonds, commodities, emerging market currencies and real estate-related instruments. “Fixed Income Instruments” include bonds, debt securities and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. The Fund will invest in such funds, securities, instruments and other investments to the extent permitted under the 1940 Act, or any exemptive relief therefrom. The Fund may invest, without limitation, in any of the Underlying PIMCO Funds (except as described below). To the extent the Fund invests in Underlying PIMCO Funds, PIMCO expects to select such Underlying PIMCO Funds without considering or canvassing the universe of available unaffiliated Acquired Funds. When determining the target allocation for the strategy, PIMCO may use proprietary quantitative models. The target allocations may include long, short, or no positions in

the underlying financial markets and asset classes specified in the models. The quantitative models are developed and maintained by PIMCO, and are subject to change over time without notice in PIMCO’s discretion. PIMCO also retains discretion over the final target asset allocation and the implementation of the target asset allocation, which may include positions that are different from target allocations determined by quantitative models.

The Fund may invest in inflation-indexed bonds of varying maturities issued by the U.S. and non-U.S. governments, their agencies or instrumentalities and corporations. Inflation-indexed bonds are fixed income securities that are structured to provide protection against inflation. The value of the bond’s principal or the interest income paid on the bond is adjusted to track changes in an official inflation measure. The U.S. Treasury uses the Consumer Price Index for Urban Consumers as the inflation measure. Inflation-indexed bonds issued by a foreign government are generally adjusted to reflect a comparable inflation index, calculated by that government. To mitigate the negative effects of inflation, the Fund seeks concurrent exposure to a broad spectrum of asset classes and other investments.

The Fund may invest up to 25% of its total assets in equity-related investments (including investment in common stock, preferred securities, equity securities of real estate investment trusts (“REITs”) and/or investment in the Domestic Equity-Related Underlying PIMCO Funds, the International Equity-Related Underlying PIMCO Funds and the PIMCO RealEstateRealReturn Strategy Fund, an Underlying PIMCO Fund, and in other equity-related Acquired Funds). With respect to its direct or indirect (through a fund) investments in equity securities, there is no limitation on the market capitalization range of the issuers in which the Fund may invest. The Fund may invest up to 50% of its total assets in commodity-related investments (including investment in the PIMCO Cayman Commodity Fund VII, Ltd., a wholly-owned subsidiary of the Fund organized under the laws of the Cayman Islands (the “Subsidiary”), and the PIMCO CommoditiesPLUS® Strategy Fund and PIMCO Commodity RealReturn Strategy Fund®, each an Underlying PIMCO Fund). The Subsidiary is advised by PIMCO and primarily invests in commodity-linked derivative instruments backed by a portfolio of Fixed Income Instruments and may also invest directly in commodities. As discussed in greater detail elsewhere in the prospectus, the Subsidiary (unlike the Fund) may invest without limitation in commodity-linked swap agreements, other commodity-linked derivative instruments and directly in commodities. In order to comply with certain issuer diversification limits imposed by the Internal Revenue Code, the Fund may invest up to 25% of its total assets in the Subsidiary. The Fund will normally limit its net exposure to gold to 25% of its total assets. The Fund may invest, without limitation, in securities denominated in foreign currencies and in U.S. dollar-denominated securities of foreign issuers. The Fund will normally limit its foreign currency exposure (from non-U.S. dollar-denominated securities or currencies) to 25% of its total assets. The Fund may invest, without limitation, in high yield securities (“junk bonds”). The Fund may invest, without limitation, in securities and instruments that are economically

2 Summary Prospectus | PIMCO Funds

Summary Prospectus

tied to emerging market countries. The Fund may purchase and sell securities on a when-issued, delayed delivery or forward commitment basis and may engage in short sales.

The Fund’s assets are not allocated according to a predetermined blend of shares of the Acquired Funds and/or direct investments in securities, instruments and other investments. Instead, when making allocation decisions among the Acquired Funds, securities, instruments and other investments, PIMCO considers various qualitative and quantitative factors relating to the U.S. and non-U.S. economies, and securities and commodities markets. These factors include projected growth trends in the U.S. and non-U.S. economies, forecasts for interest rates and the relationship between short- and long-term interest rates (yield curve), current and projected trends in inflation, relative valuation levels in the equity, fixed income, commodity and real estate markets and various segments within those markets, the outlook and projected growth of various industrial sectors, information relating to business cycles, borrowing needs and the cost of capital, political trends, data relating to trade balances, and labor information. PIMCO uses these factors to help determine the Fund’s target asset allocation and to identify potentially attractive relative value and risk hedging strategies. PIMCO has the flexibility to reallocate the Fund’s assets among any or all of the investment exposures represented by affiliated or unaffiliated funds, or invest directly in securities, instruments and other investments, based on its ongoing analyses of the global economy and financial markets. While these analyses are performed daily, material shifts in investment exposures typically take place over longer periods of time.

Once the target asset allocation, relative value strategies and risk hedging strategies have been determined, PIMCO then evaluates various combinations of affiliated or unaffiliated funds, securities, instruments and other investments to obtain the desired exposures and invests accordingly.

Principal Risks

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund include risks from direct investments and/or indirect exposure through investment in Acquired Funds. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

The following risks are principal risks of investing in the Fund.

Allocation Risk: the risk that a Fund could lose money as a result of less than optimal or poor asset allocation decisions. The Fund could miss attractive investment opportunities by underweighting markets that subsequently experience significant returns and could lose value by overweighting markets that subsequently experience significant declines

Acquired Fund Risk: the risk that the Fund's performance is closely related to the risks associated with the securities and other investments held by the Acquired Funds and that the ability of the Fund to achieve its investment objective will depend upon the ability of the Acquired Funds to achieve their investment objectives. In addition, the Fund's performance will be reduced by the Fund's proportionate amount of the expenses of any Acquired Funds in which it invests

The following are principal risks of investing in the Fund that include risks from direct investments and/or indirect exposure through investment in Acquired Funds.

Interest Rate Risk: the risk that fixed income securities will fluctuate in value because of a change in interest rates; a fund with a longer average portfolio duration will be more sensitive to changes in interest rates than a fund with a shorter average portfolio duration

Call Risk: the risk that an issuer may exercise its right to redeem a fixed income security earlier than expected (a call). Issuers may call outstanding securities prior to their maturity for a number of reasons (e.g., declining interest rates, changes in credit spreads and improvements in the issuer’s credit quality). If an issuer calls a security that the Fund has invested in, the Fund may not recoup the full amount of its initial investment or may not realize the full anticipated earnings from the investment and may be forced to reinvest in lower-yielding securities, securities with greater credit risks or securities with other, less favorable features

Credit Risk: the risk that the Fund could lose money if the issuer or guarantor of a fixed income security, or the counterparty to a derivative contract, or the issuer or guarantor of collateral, is unable or unwilling, or is perceived (whether by market participants, rating agencies, pricing services or otherwise) as unable or unwilling, to meet its financial obligations

High Yield and Distressed Company Risk: the risk that high yield securities and unrated securities of similar credit quality (commonly known as “junk bonds”) and securities of distressed companies may be subject to greater levels of credit, issuer and liquidity risks. Securities of distressed companies include both debt and equity securities. High yield securities and debt securities of distressed companies are considered primarily speculative with respect to the issuer’s continuing ability to make principal and interest payments. Distressed companies may be engaged in restructurings or bankruptcy proceedings

Market Risk: the risk that the value of securities owned by the Fund may go up or down, sometimes rapidly or unpredictably, due to factors affecting securities markets generally or particular industries

Issuer Risk: the risk that the value of a security may decline for a reason directly related to the issuer, such as management performance, changes in financial condition or credit rating, financial leverage, reputation or reduced demand for the issuer’s goods or services

Liquidity Risk: the risk that a particular investment may be difficult to purchase or sell and that the Fund may be unable to sell illiquid investments at an advantageous time or price or achieve its desired level of exposure to a certain sector. Liquidity risk may result from the lack of an active market, reduced number and capacity of traditional market participants to make a market in fixed income securities, and may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity

August 1, 2024 (as supplemented June 2, 2025) | SUMMARY PROSPECTUS 3

PIMCO Inflation Response Multi-Asset Fund

Derivatives Risk: the risk of investing in derivative instruments (such as forwards, futures, swaps and structured securities) and other similar investments, including leverage, liquidity, interest rate, market, counterparty (including credit), operational, legal and management risks, and valuation complexity. Changes in the value of a derivative or other similar investment may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. Changes in the value of a derivative or other similar instrument may also create margin delivery or settlement payment obligations for the Fund. The Fund’s use of derivatives or other similar investments may result in losses to the Fund, a reduction in the Fund’s returns and/or increased volatility. Non-centrally-cleared over-the-counter (“OTC”) derivatives or other similar investments are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for non-centrally-cleared OTC derivatives or other similar investments. The primary credit risk on derivatives or other similar investments that are exchange-traded or traded through a central clearing counterparty resides with the Fund's clearing broker or the clearinghouse. Changes in regulation relating to a registered fund’s use of derivatives and related instruments could potentially limit or impact the Fund’s ability to invest in derivatives, limit the Fund’s ability to employ certain strategies that use derivatives or other similar investments and/or adversely affect the value of derivatives or other similar investments and the Fund’s performance

Model Risk: the risk that the Fund’s investment models used in making investment allocation decisions may not adequately take into account certain factors, or may contain design flaws or faulty assumptions, and may rely on incomplete or inaccurate data inputs, any of which may result in a decline in the value of an investment in the Fund

Commodity Risk: the risk that investing in commodity-linked derivative instruments and commodities, either directly or indirectly through the Subsidiary, may subject the Fund to greater volatility than investments in traditional securities. The value of commodity-linked derivative instruments or commodities may be affected by changes in overall market movements, foreign currency exchange rates, commodity index volatility, changes in inflation, interest rates, or supply and demand factors affecting a particular industry or commodity market, such as drought, floods, weather, livestock disease, pandemics and public health emergencies, embargoes, taxation, war, terrorism, cyber hacking, economic and political developments, environmental proceedings, tariffs, changes in storage costs, availability of transportation systems, and international economic, political and regulatory developments. Investments in commodities can also present risks associated with transportation and delivery, custody, storage and maintenance, illiquidity, and the unavailability of accurate market valuations of the commodity

Equity Risk: the risk that the value of equity or equity-related securities, such as common stocks and preferred securities, may decline

due to general market conditions which are not specifically related to a particular company or to factors affecting a particular industry or industries. Equity or equity-related securities generally have greater price volatility than fixed income securities. In addition, preferred securities may be subject to greater credit risk or other risks, such as risks related to deferred and omitted distributions, limited voting rights, liquidity, interest rates, regulatory changes and special redemption rights

Mortgage-Related and Other Asset-Backed Securities Risk: the risks of investing in mortgage-related and other asset-backed securities, including interest rate risk, extension risk, prepayment risk and credit risk. The Fund may invest in any tranche of mortgage-related and other asset-backed securities, including junior and/or equity tranches (to the extent consistent with the other of the Fund’s guidelines), which generally carry higher levels of the foregoing risks

Foreign (Non-U.S.) Investment Risk: the risk that investing in foreign (non-U.S.) securities may result in the Fund experiencing more rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. companies, due to smaller markets, differing reporting, accounting and auditing standards, increased risk of delayed settlement of portfolio transactions or loss of certificates of portfolio securities, and the risk of unfavorable foreign government actions, including nationalization, expropriation or confiscatory taxation, currency blockage, political changes, diplomatic developments or the imposition of sanctions and other similar measures. Foreign securities may also be less liquid and more difficult to value than securities of U.S. issuers

Real Estate Risk: the risk that the Fund’s investments in real estate investment trusts (“REITs”) or real estate-linked derivative instruments will subject the Fund to risks similar to those associated with direct ownership of real estate, including losses from casualty or condemnation, and changes in local and general economic conditions, supply and demand, interest rates, zoning laws, regulatory limitations on rents, property taxes and operating expenses. The Fund’s investments in REITs or real estate-linked derivative instruments subject it to management and tax risks. In addition, privately traded REITs subject the Fund to liquidity and valuation risk

Emerging Markets Risk: the risk of investing in emerging market securities, primarily increased foreign (non-U.S.) investment risk

Sovereign Debt Risk: the risk that investments in fixed income instruments issued by sovereign entities may decline in value as a result of default or other adverse credit event resulting from an issuer’s inability or unwillingness to make principal or interest payments in a timely fashion

Currency Risk: the risk that foreign (non-U.S.) currencies will change in value relative to the U.S. dollar and affect the Fund’s investments in foreign (non-U.S.) currencies or in securities that trade in, and receive revenues in, or in derivatives that provide exposure to, foreign (non-U.S.) currencies

4 Summary Prospectus | PIMCO Funds

Summary Prospectus

Leveraging Risk: the risk that certain transactions of the Fund, such as reverse repurchase agreements, loans of portfolio securities, and the use of when-issued, delayed delivery or forward commitment transactions, or derivative instruments, may give rise to leverage, magnifying gains and losses and causing the Fund to be more volatile than if it had not been leveraged. This means that leverage entails a heightened risk of loss

Management Risk: the risk that the investment techniques and risk analyses applied by PIMCO, including the use of quantitative models or methods, will not produce the desired results and that actual or potential conflicts of interest, legislative, regulatory, or tax restrictions, policies or developments may affect the investment techniques available to PIMCO and the individual portfolio managers in connection with managing the Fund and may cause PIMCO to restrict or prohibit participation in certain investments. There is no guarantee that the investment objective of the Fund will be achieved

Inflation-Indexed Security Risk: the risk that inflation-indexed debt securities are subject to the effects of changes in market interest rates caused by factors other than inflation (real interest rates). In general, the value of an inflation-indexed security, including TIPS, tends to decrease when real interest rates increase and can increase when real interest rates decrease. Interest payments on inflation-indexed securities are unpredictable and will fluctuate as the principal and interest are adjusted for inflation. There can be no assurance that the inflation index used will accurately measure the real rate of inflation in the prices of goods and services. Any increase in the principal amount of an inflation-indexed debt security will be considered taxable ordinary income, even though the Fund will not receive the principal until maturity

Short Exposure Risk: the risk of entering into short sales or other short positions, including the potential loss of more money than the actual cost of the investment, and the risk that the third party to the short sale or other short position will not fulfill its contractual obligations, causing a loss to the Fund

Tax Risk: the risk that the tax treatment of swap agreements and other derivative instruments, such as commodity-linked derivative instruments, including commodity index-linked notes, swap agreements, commodity options, futures, and options on futures, may be affected by future regulatory or legislative changes that could affect whether income from such investments is “qualifying income” under Subchapter M of the Internal Revenue Code, or otherwise affect the character, timing and/or amount of the Fund’s taxable income or gains and distributions

Subsidiary Risk: the risk that, by investing in the Subsidiary, the Fund is indirectly exposed to the risks associated with the Subsidiary’s investments. The Subsidiary is not registered under the Investment Company Act of 1940, as amended (the “1940 Act”) and may not be subject to all the investor protections of the 1940 Act. There is no guarantee that the investment objective of the Subsidiary will be achieved

Value Investing Risk: a value stock may decrease in price or may not increase in price as anticipated by PIMCO if it continues to be undervalued by the market or the factors that the portfolio manager believes will cause the stock price to increase do not occur

Arbitrage Risk: the risk that securities purchased pursuant to an arbitrage strategy intended to take advantage of a perceived relationship between the value of two securities may not perform as expected

Convertible Securities Risk: as convertible securities share both fixed income and equity characteristics, they are subject to risks to which fixed income and equity investments are subject. These risks include equity risk, interest rate risk and credit risk

Small-Cap and Mid-Cap Company Risk: the risk that the value of securities issued by small-capitalization and mid-capitalization companies may go up or down, sometimes rapidly and unpredictably, due to narrow markets and limited managerial and financial resources

Gold-Related Risk: the risk that investments tied to the price of gold may fluctuate substantially over short periods of time or be more volatile than other types of investments due to, among other matters, changes in inflation or inflation expectations or other economic, financial and political factors in the U.S. and foreign (non-U.S.) countries

Exchange-Traded Fund Risk: the risk that an exchange-traded fund may not track the performance of the index it is designed to track, among other reasons, because of exchange rules, market prices of shares of an exchange-traded fund may fluctuate rapidly and materially, or shares of an exchange-traded fund may trade significantly above or below net asset value, any of which may cause losses to the Fund invested in the exchange-traded fund

LIBOR Transition Risk: the risk related to the discontinuation and replacement of the London Interbank Offered Rate (“LIBOR”). Certain instruments held by the Fund rely or relied in some fashion upon LIBOR. Although the transition process away from LIBOR for most instruments has been completed, some LIBOR use is continuing and there are potential effects related to the transition away from LIBOR or the continued use of LIBOR on the Fund, or on certain instruments in which the Fund invests, which can be difficult to ascertain and could result in losses to the Fund

Please see “Description of Principal Risks” in the Fund's prospectus for a more detailed description of the risks of investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance Information

The performance information shows summary performance information for the Fund in a bar chart and an Average Annual Total Returns table. The information provides some indication of the risks of investing in the Fund by showing changes in its performance from year to year and by showing how the Fund’s average annual returns compare with the returns of certain indexes. Absent any applicable fee waivers and/or

August 1, 2024 (as supplemented June 2, 2025) | SUMMARY PROSPECTUS 5

PIMCO Inflation Response Multi-Asset Fund

expense limitations, performance would have been lower. The bar chart shows performance of the Fund’s Institutional Class shares. For periods prior to the inception date of I-3 shares (September 15, 2022), performance information shown in the table for I-3 shares is based on the performance of the Fund’s Institutional Class shares, adjusted to reflect the fees and expenses paid by I-3 shares. The Administrative Class shares of the Fund have not commenced operations as of the date of this prospectus. Performance for Class A shares in the Average Annual Total Returns table reflects the impact of sales charges.The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

In addition to the Fund’s performance, the Average Annual Total Returns table includes performance of: (i) a broad-based securities market index (i.e., a regulatory index) and (ii) a supplemental index. It is not possible to invest directly in an unmanaged index. Effective July 24, 2024, the Fund’s regulatory index is the Bloomberg U.S. Aggregate Index. The Fund’s regulatory index is shown in connection with certain regulatory requirements to provide a broad measure of market performance. The Bloomberg U.S. Aggregate Index represents securities that are SEC-registered, taxable, and U.S. dollar denominated. The index covers the U.S. investment grade fixed rate bond market, with index components for government and corporate securities, mortgage pass-through securities, and asset-backed securities. These major sectors are subdivided into more specific indices that are calculated and reported on a regular basis. The supplemental index shown is the Inflation Response Index. The Inflation Response Index represents a diversified basket of asset classes that serve either as an explicit or as an implicit hedge against inflation and is comprised of a blend of 45% Bloomberg U.S. TIPS Index, 20% Bloomberg Commodity Index Total Return, 15% JPMorgan Emerging Local Markets Index Plus (Unhedged), 10% Dow Jones U.S. Select REIT Total Return Index, and 10% Bloomberg Gold Subindex Total Return Index. The Bloomberg U.S. TIPS Index is an unmanaged market index comprised of all U.S. Treasury Inflation Protected Securities (“TIPS”) rated investment grade (Baa3 or better), that have at least one year to final maturity, and at least $500 million par amount outstanding. The Bloomberg Commodity Index Total Return is an unmanaged index composed of futures contracts on a number of physical commodities, which is designed to be a highly liquid and diversified benchmark for commodities as an asset class. The JPMorgan Emerging Local Markets Index Plus (Unhedged) tracks total returns for local-currency denominated money market instruments in 22 emerging market countries with at least US$10 billion of external trade. The Dow Jones U.S. Select Real Estate Investment Trust (REIT) Total Return Index, a subset of the Dow Jones Americas Select Real Estate Securities Index (RESI) that includes only REITs and REIT-like securities, seeks to measure the performance of publicly-traded real estate securities. The Dow Jones U.S. Select REIT Total Return Index is designed to serve as a proxy for direct real estate investment. The Bloomberg Gold Subindex Total Return Index reflects the return on fully-collateralized positions in the underlying commodity futures.

Performance for the Fund is updated daily and quarterly and may be obtained as follows: daily and quarterly updates on the net asset value and performance page at https://www.pimco.com/en-us/product-finder.

Calendar Year Total Returns — Institutional Class

Best Quarter	June 30, 2020	9.53%
Worst Quarter	March 31, 2020	-11.03%
Year-to-Date	June 30, 2024	2.98%

Average Annual Total Returns (for periods ended 12/31/23)

	1 Year	5 Years	10 Years
Institutional Class Return Before Taxes	6.50%	6.71%	4.24%
Institutional Class Return After Taxes on Distributions(1)	6.45%	4.44%	1.88%
Institutional Class Return After Taxes on Distributions and Sales of Fund Shares(1)	3.85%	4.25%	2.18%
I-2 Return Before Taxes	6.37%	6.62%	4.14%
I-3 Return Before Taxes	6.42%	6.58%	4.13%
Class A Return Before Taxes	0.13%	5.02%	3.17%
Bloomberg U.S. Aggregate Index (reflects no deductions for fees, expenses or taxes)	5.53%	1.10%	1.81%
45% Bloomberg U.S. TIPS Index, 20% Bloomberg Commodity Index Total Return, 15% JPMorgan Emerging Local Markets Index Plus (Unhedged), 10% Dow Jones U.S. Select REIT Total Return Index, 10% Bloomberg Gold Subindex Total Return Index (reflects no deductions for fees, expenses or taxes)	4.22%	4.90%	2.36%

After-tax returns are calculated using the highest historical individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. In some cases the return after taxes may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of Fund shares at the end of the measurement period. After-tax returns are for Institutional Class shares only. After-tax returns for other classes will vary.

6 Summary Prospectus | PIMCO Funds

Summary Prospectus

Investment Adviser/Portfolio Managers

PIMCO serves as the investment adviser for the Fund. The Fund’s portfolio is jointly and primarily managed by Steve Rodosky, Greg Sharenow, Andrew DeWitt, Daniel He and Emmanuel Sharef. Messrs. Rodosky and Sharenow are Managing Directors of PIMCO, and Messrs. DeWitt and He and Dr. Sharef are Executive Vice Presidents of PIMCO. Mr. Rodosky has managed the Fund since January 2019. Mr. Sharenow has managed the Fund since February 2022. Mr. DeWitt has managed the Fund since June 2025. Mr. He has managed the Fund since December 2019. Dr. Sharef has managed the Fund since February 2022.

Purchase and Sale of Fund Shares

Fund shares may be purchased or sold (redeemed) on any business day (normally any day when the New York Stock Exchange (“NYSE”) is open). Generally, purchase and redemption orders for Fund shares are processed at the net asset value next calculated after an order is received by the Fund.

Institutional Class, I-2, I-3 and Administrative Class

The minimum initial investment for Institutional Class, I-2, I-3 and Administrative Class shares of the Fund is $1 million, except that the minimum initial investment may be modified for certain financial firms that submit orders on behalf of their customers.

You may sell (redeem) all or part of your Institutional Class, I-2, I-3 and Administrative Class shares of the Fund on any business day. If you are the registered owner of the shares on the books of the Fund, depending on the elections made on the Account Application, you may sell by:

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Sending a written request by regular mail to:

PIMCO Funds
P.O. Box 219024, Kansas City, MO 64121-9024
or by overnight mail to:
PIMCO Funds c/o SS&C Global Investor and Distribution Solutions, Inc.

430 W 7th Street, STE 219024, Kansas City, MO 64105-1407

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Calling us at 888.87.PIMCO and a Shareholder Services associate will assist you

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Sending a fax to our Shareholder Services department at 1.816.421.2861

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Sending an e-mail to piprocess@dstsystems.com

Class A

The minimum initial investment for Class A shares of the Fund is $1,000. The minimum subsequent investment for Class A shares is $50. The minimum initial investment may be modified for certain financial firms that submit orders on behalf of their customers. You may purchase or sell (redeem) all or part of your Class A shares through a broker-dealer, or other financial firm, or, if you are the registered owner of the shares on the books of the Fund, by regular mail to PIMCO Funds, P.O. Box 219294, Kansas City, MO 64121-9294 or overnight mail to PIMCO Funds, c/o SS&C Global Investor and Distribution Solutions, Inc., 430 W. 7th Street, STE 219294, Kansas City, MO 64105-1407. The Fund reserves the right to require payment by wire or U.S. Bank check in connection with accounts opened directly with the Fund by Account Application.

Tax Information

The Fund’s distributions are generally taxable to you as ordinary income, capital gains, or a combination of the two, unless you are investing through a tax-deferred arrangement, such as a 401(k) plan or an individual retirement account, in which case distributions may be taxable upon withdrawal.

Payments to Broker-Dealers and Other Financial Firms

If you purchase shares of the Fund through a broker-dealer or other financial firm (such as a bank), the Fund and/or its related companies (including PIMCO) may pay the financial firm for the sale of those shares of the Fund and/or related services. These payments may create a conflict of interest by influencing the broker-dealer or other financial firm and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial firm’s website for more information.

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