UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT

INVESTMENT COMPANIES

Investment Company Act file number: 811-23314

PIMCO Flexible Municipal Income Fund

(Exact name of registrant as specified in charter)

1633 Broadway, New York, NY 10019

(Address of principal executive offices)

Bijal Y. Parikh

Treasurer (Principal Financial & Accounting Officer)

650 Newport Center Drive

Newport Beach, CA 92660

(Name and address of agent for service)

Copies to:

David C. Sullivan

Ropes & Gray LLP

Prudential Tower

800 Boylston Street

Boston, MA 02199

Registrant’s telephone number, including area code: (844) 337-4626

Date of fiscal year end: December 31

Date of reporting period: June 30, 2023

Form N-CSR is to be used by management investment companies to file reports with the Commission not later than 10 days after the transmission to stockholders of any report that is required to be transmitted to stockholders under Rule 30e-1 under the Investment Company Act of 1940 (17 CFR 270.30e-1). The Commission may use the information provided on Form N-CSR in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-CSR, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-CSR unless the Form displays a currently valid Office of Management and Budget (“OMB”) control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

The following is a copy of the report transmitted to shareholders pursuant to Rule 30e-1 under the Investment Company Act of 1940, as amended (the “1940 Act”) (17 CFR 270.30e-1).

PIMCO MUNICIPAL INTERVAL FUNDS

Semiannual Report

June 30, 2023

PIMCO California Flexible Municipal Income Fund

PIMCO Flexible Municipal Income Fund

Table of Contents

Market Insights

Dear Shareholder,

This semiannual report covers the six-month reporting period ended June 30, 2023 (the “reporting period”). On the subsequent pages, you will find details regarding investment results and a discussion of certain factors that affected performance during the reporting period.

Amid elevated inflation in many countries during the reporting period, the global economy faced challenges from higher interest rates, tighter credit conditions stemming from the turmoil in the banking sector (especially in the United States (“U.S.”)), and geopolitical concerns. While the U.S. economy showed signs of resilience, some European economies experienced slower growth over the reporting period.

Continued central bank efforts to combat inflation

While inflation remained elevated over the reporting period, many central banks raised interest rates to rein in rising prices. The U.S. Federal Reserve (the “Fed”) raised the federal funds rate at 10 consecutive meetings, beginning in March 2022 through May 2023. In June 2023, the Fed then paused from raising rates in order to “assess additional information and its implications for monetary policy.” Meanwhile, the Bank of England and European Central Bank raised interest rates for the 13^th and eighth consecutive time, respectively, as of June 2023. In contrast, the Bank of Japan maintained its accommodative monetary policy stance.

Mixed financial market returns

The yield on the benchmark 10-year U.S. Treasury declined over the reporting period, while 10-year bond yields in most other developed market countries increased. The overall global credit bond market delivered positive total returns. Higher-rated global bonds underperformed lower-rated bonds. Global equities rallied, while commodity prices were volatile and produced mixed returns. The U.S. dollar weakened against the euro and the British pound, but appreciated against the Japanese yen.

Amid evolving conditions, we will continue to work diligently to navigate global markets and manage the assets that you have entrusted with us. We encourage you to speak with your financial advisor about your goals, and visit global.pimco.com for our latest insights.

Sincerely,

 

Deborah A. DeCotis		Eric D. Johnson
Chair of the Board of Trustees		President

Past performance is no guarantee of future results. Unless otherwise noted, index returns reflect the reinvestment of income distributions and capital gains, if any, but do not reflect fees, brokerage commissions or other expenses of investing. It is not possible to invest directly in an unmanaged index.

Statements concerning financial market trends are based on current market conditions, which will fluctuate. There is no guarantee that these investment strategies will work under all market conditions or are appropriate for all investors and each investor should evaluate their ability to invest for the long-term, especially during periods of downturn in the market. Outlook and strategies are subject to change without notice.

Important Information About the Funds

We believe that bond funds have an important role to play in a well-diversified investment portfolio. It is important to note, however, that in an environment where interest rates may trend upward, rising rates would negatively impact the performance of most bond funds, and fixed-income securities and other instruments held by a Fund are likely to decrease in value. A wide variety of factors can cause interest rates or yields of U.S. Treasury securities (or yields of other types of bonds) to rise (e.g., central bank monetary policies, inflation rates, general economic conditions, etc.). In addition, changes in interest rates can be sudden and unpredictable, and there is no guarantee that Fund management will anticipate such movement accurately. A Fund may lose money as a result of movements in interest rates.

As of the date of this report, interest rates in the United States and many parts of the world, including certain European countries, continue to increase. In efforts to combat inflation, the U.S. Federal Reserve raised interest rates multiple times in 2022 and 2023. Thus, the Funds currently face a heightened level of risk associated with rising interest rates and/or bond yields. This could be driven by a variety of factors, including but not limited to central bank monetary policies, changing inflation or real growth rates, general economic conditions, increasing bond issuances or reduced market demand for low yielding investments. Further, while bond markets have steadily grown over the past three decades, dealer inventories of corporate bonds are near historic lows in relation to market size. As a result, there has been a significant reduction in the ability of dealers to “make markets.”

Bond funds and individual bonds with a longer duration (a measure used to determine the sensitivity of a security’s price to changes in interest rates) tend to be more sensitive to changes in interest rates, usually making them more volatile than securities or funds with shorter durations. All of the factors mentioned above, individually or collectively, could lead to increased volatility and/or lower liquidity in the fixed income markets or negatively impact a Fund’s performance or cause a Fund to incur losses.

Investing in the municipal bond market involves the risks of investing in debt securities generally and certain other risks. The amount of public information available about the municipal bonds in which a Fund may invest is generally less than that for corporate equities or bonds, and the investment performance of a Fund’s investment in municipal bonds may therefore be more dependent on the analytical abilities of Pacific Investment Management Company LLC (“PIMCO” or the “Manager”) than its investments in taxable bonds. The secondary market for municipal bonds also tends to be less well-developed or liquid than many other securities markets, which may adversely affect a Fund’s ability to sell its bonds at attractive prices.

The ability of municipal issuers to make timely payments of interest and principal may be diminished during general economic downturns, by litigation, legislation or political events, or by the bankruptcy of the issuer. Issuers of municipal securities also might seek protection under the bankruptcy laws. In the event of bankruptcy of such an issuer, the Funds could experience delays in collecting principal and interest and a Fund may not, in all circumstances, be able to collect all principal and interest to which it is entitled.

A Fund that has substantial exposures to California municipal bonds may be affected significantly by economic, regulatory or political developments affecting the ability of California issuers to pay interest or repay principal. Certain issuers of California municipal bonds have experienced serious financial difficulties in the past and reoccurrence of these difficulties may impair the ability of certain California issuers to pay principal or interest on their obligations. Provisions of the California

Important Information About the Funds (Cont.)

Constitution and State statutes that limit the taxing and spending authority of California governmental entities may impair the ability of California issuers to pay principal and/or interest on their obligations. While California’s economy is broad, it does have major concentrations in advanced technology, aerospace and defense-related manufacturing, trade, entertainment, real estate and financial services, and may be sensitive to economic problems affecting those industries. Future California political and economic developments, constitutional amendments, legislative measures, executive orders, administrative regulations, litigation and voter initiatives could have an adverse effect on the debt obligations of California issuers.

A Fund that has substantial exposures to New York municipal bonds may be affected significantly by economic, regulatory or political developments affecting the ability of New York issuers to pay interest or repay principal. While New York’s economy is broad, it does have concentrations in the financial services industry, and may be sensitive to economic problems affecting that industry. Certain issuers of New York municipal bonds have experienced serious financial difficulties in the past and reoccurrence of these difficulties may impair the ability of certain New York issuers to pay principal or interest on their obligations. The financial health of New York City affects that of the State, and when New York City experiences financial difficulty, it may have an adverse effect on New York municipal bonds held by a Fund. The growth rate of New York has at times been somewhat slower than the nation overall. The economic and financial condition of New York also may be affected by various financial, social, economic and political factors.

A Fund that has substantial exposures to municipal obligations issued by Puerto Rico or its political subdivisions, agencies, instrumentalities, or public corporations may be affected significantly by economic, market, political, and social conditions in Puerto Rico. Puerto Rico currently is experiencing significant fiscal and economic challenges, including substantial debt service obligations, high levels of unemployment, underfunded public retirement systems, and persistent government budget deficits. These challenges may negatively affect the value of a Fund’s investments in Puerto Rico municipal securities. Legislation, including legislation that would allow Puerto Rico to restructure its municipal debt obligations, thus increasing the risk that Puerto Rico may never pay off municipal indebtedness, or may pay only a small fraction of the amount owed, could also impact the value of the Fund’s investments in Puerto Rico municipal securities.

Classifications of the Funds’ portfolio holdings in this report are made according to financial reporting standards. The classification of a particular portfolio holding as shown in the Allocation Breakdown and Consolidated Schedule of Investments and other sections of this report may differ from the classification used for the Funds’ compliance calculations, including those used in the Funds’ prospectus, investment objectives, regulatory, and other investment limitations and policies, which may be based on different asset class, sector or geographical classifications. Each Fund is separately monitored for compliance with respect to prospectus and regulatory requirements.

The geographical classification of foreign (non-U.S.) securities in this report, if any, are classified by the country of incorporation of a holding. In certain instances, a security’s country of incorporation may be different from its country of economic exposure.

In February 2022, Russia launched an invasion of Ukraine. As a result, Russia and other countries, persons and entities that have provided material aid to Russia’s aggression against Ukraine have been the subject of economic sanctions and import and export controls imposed by countries throughout the world, including the United States. Such measures have had and may continue to

have an adverse effect on the Russian, Belarusian and other securities and economies, which may, in turn, negatively impact a Fund. The extent, duration and impact of Russia’s military action in Ukraine, related sanctions and retaliatory actions are difficult to ascertain, but could be significant and have severe adverse effects on the region, including significant adverse effects on the regional, European, and global economies and the markets for certain securities and commodities, such as oil and natural gas, as well as other sectors. Further, a Fund may have investments in securities and instruments that are economically tied to the region and may have been negatively impacted by the sanctions and counter-sanctions by Russia, including declines in value and reductions in liquidity. The sanctions may cause a Fund to sell portfolio holdings at a disadvantageous time or price or to continue to hold investments that a Fund may no longer seek to hold. PIMCO will continue to actively manage these positions in the best interests of a Fund and its shareholders.

The Funds may invest in certain instruments that rely in some fashion upon the London Interbank Offered Rate (“LIBOR”). LIBOR was traditionally an average interest rate, determined by the ICE Benchmark Administration, that banks charge one another for the use of short-term money. In March 2021, the United Kingdom’s Financial Conduct Authority, which regulates LIBOR, announced plans to ultimately phase out the use of LIBOR. Although the transition process away from LIBOR for many instruments has been completed, some LIBOR use is continuing and there are potential effects related to the transition away from LIBOR or continued use of LIBOR on a Fund, or on certain instruments in which a Fund invests, which can be difficult to ascertain, and may vary depending on factors that include, but are not limited to: (i) existing fallback or termination provisions in individual contracts and (ii) whether, how, and when industry participants adopt new reference rates for affected instruments. The transition of investments from LIBOR to a replacement rate as a result of amendment, application of existing fallbacks, statutory requirements or otherwise may also result in a reduction in the value of certain instruments held by a Fund or a reduction in the effectiveness of related Fund transactions such as hedges. In addition, an instrument’s transition to a replacement rate could result in variations in the reported yields of a Fund that holds such instrument. Any such effects of the transition away from LIBOR, as well as other unforeseen effects, could result in losses to a Fund.

U.S. and global markets recently have experienced increased volatility, including as a result of the recent failures of certain U.S. and non-U.S. banks, which could be harmful to the Funds and issuers in which they invest. For example, if a bank at which a Fund or issuer has an account fails, any cash or other assets in bank or custody accounts, which may be substantial in size, could be temporarily inaccessible or permanently lost by the Fund or issuer. If a bank that provides a subscription line credit facility, asset-based facility, other credit facility and/or other services to an issuer or to a fund fails, the issuer or fund could be unable to draw funds under its credit facilities or obtain replacement credit facilities or other services from other lending institutions with similar terms.

Issuers in which a Fund may invest can be affected by volatility in the banking sector. Even if banks used by issuers in which the Funds invest remain solvent, continued volatility in the banking sector could contribute to, cause or intensify an economic recession, increase the costs of capital and banking services or result in the issuers being unable to obtain or refinance indebtedness at all or on as favorable terms as could otherwise have been obtained. Conditions in the banking sector are evolving, and the scope of any potential impacts to the Funds and issuers, both from market conditions and also potential legislative or regulatory responses, are uncertain. Such conditions and responses, as well as a changing interest rate environment, can 30 contribute to decreased market liquidity and erode the value of certain holdings, including those of U.S. and non-U.S. banks.

Important Information About the Funds (Cont.)

Continued market volatility and uncertainty and/or a downturn in market and economic and financial conditions, as a result of developments in the banking sector or otherwise (including as a result of delayed access to cash or credit facilities), could have an adverse impact on the Funds and issuers in which they invest.

On each Fund Summary page in this Shareholder Report, the Average Annual Total Return table and Cumulative Returns chart measure performance assuming that any dividend and capital gain distributions were reinvested. Total return is calculated by determining the percentage change in NAV in the specific period. Returns do not reflect the deduction of taxes that a shareholder would pay on (i) Fund distributions or (ii) the sale of Fund shares. Total return for a period of more than one year represents the average annual total return. Performance shown is net of fees and expenses. Historical performance for a Fund or share class thereof may have been positively impacted by fee waivers or expense limitations in place during some or all of the periods shown, if applicable. Future performance (including total return or yield) and distributions may be negatively impacted by the expiration or reduction of any such fee waivers or expense limitations.

The dividend rate that a Fund pays on its common shares may vary as portfolio and market conditions change, and will depend on a number of factors, including without limit the amount of the Fund’s undistributed net investment income and net short- and long-term capital gains, as well as the costs of any leverage obtained by a Fund. As portfolio and market conditions change, the rate of distributions on the common shares and a Fund’s dividend policy could change. There can be no assurance that a change in market conditions or other factors will not result in a change in a Fund’s distribution rate or that the rate will be sustainable in the future.

The following table discloses the inception dates and diversification status of the Funds:

An investment in a Fund is not a bank deposit and is not guaranteed or insured by the Federal Deposit Insurance Corporation or any other government agency. It is possible to lose money on investments in a Fund.

The Trustees are responsible generally for overseeing the management of the Funds. The Trustees authorize the Funds to enter into service agreements with the Manager and other service providers in order to provide, and in some cases authorize service providers to procure through other parties, necessary or desirable services on behalf of the Funds. Shareholders are not parties to or third-party beneficiaries of such service agreements. Neither a Fund’s prospectus or Statement of Additional Information (“SAI”), any press release or shareholder report, any contracts filed as exhibits to the Funds’ registration statement, nor any other communications, disclosure documents or regulatory filings (including this report) from or on behalf of the Funds creates a contract between or among any shareholders of a Fund, on the one hand, and the Funds, a service provider to a Fund, and/or the Trustees or officers of the Funds, on the other hand.

The Trustees (or the Funds and its officers, service providers or other delegates acting under authority of the Trustees) may amend its most recent prospectus or use a new prospectus or SAI with respect

to the Funds, adopt and disclose new or amended policies and other changes in press releases and shareholder reports and/or amend, file and/or issue any other communications, disclosure documents or regulatory filings, and may amend or enter into any contracts to which a Fund is a party, and interpret the investment objective(s), policies, restrictions and contractual provisions applicable to a Fund, without shareholder input or approval, except in circumstances in which shareholder approval is specifically required by law (such as changes to fundamental investment policies) or where a shareholder approval requirement was specifically disclosed in the Funds’ prospectus, SAI or shareholder report and is otherwise still in effect.

PIMCO has adopted written proxy voting policies and procedures (“Proxy Policy”) as required by Rule 206(4)-6 under the Investment Advisers Act of 1940, as amended. The Proxy Policy has been adopted by the Funds as the policies and procedures that PIMCO will use when voting proxies on behalf of the Funds.

A description of the policies and procedures that PIMCO uses to vote proxies relating to portfolio securities of each Fund, and information about how each Fund voted proxies relating to portfolio securities held during the most recent twelve-month period ended June 30th, are available without charge, upon request, by calling the Funds at (844) 312-2113, on the Funds’ website at www.pimco.com, and on the Securities and Exchange Commission’s (“SEC”) website at www.sec.gov.

The Funds file their complete schedules of portfolio holdings with the SEC for the first and third quarters of each fiscal year as an exhibit to their reports on Form N-PORT. The Funds’ Form N-PORT reports are available to the public on the SEC’s website at www.sec.gov and on PIMCO’s website at www.pimco.com, and upon request by calling PIMCO at (844) 312-2113.

SEC rules allow shareholder reports to be delivered to investors by providing access to such reports online free of charge and by mailing a notice that the report is electronically available. Investors may elect to receive all reports in paper free of charge by contacting their financial intermediary or, if invested directly with a Fund, investors can inform the Fund by calling (844) 312-2113. Any election to receive reports in paper will apply to all funds held with a fund complex if invested directly with a Fund or to all funds held in the investor’s account if invested through a financial intermediary, such as a broker-dealer or bank.

In April 2020, the SEC adopted amended rules modifying the registration, communications, and offering processes for registered closed-end funds and interval funds. Among other things, the amendments: (1) permit qualifying closed-end funds to use a short-form registration statement to offer securities in eligible transactions and certain funds to qualify as Well Known Seasoned Issuers; (2) permit interval funds to pay registration fees based on net issuance of shares in a manner similar to mutual funds; (3) require closed-end funds and interval funds to include additional disclosures in their annual reports; and (4) require certain information to be filed in interactive data format. The new rules had phased compliance, with the latest requirement taking effect as of February 1, 2023.

In October 2020, the SEC adopted a rule related to the use of derivatives, short sales, reverse repurchase agreements and certain other transactions by registered investment companies that rescinds and withdraws prior guidance of the SEC and its staff regarding asset segregation and cover transactions. Subject to certain exceptions, the rule requires funds that trade derivatives and other transactions that create future payment or delivery obligations to comply with a value-at-risk leverage limit and certain derivatives risk management program and reporting requirements. These

Important Information About the Funds (Cont.)

requirements may limit the ability of the Funds to use derivatives and reverse repurchase agreements and similar financing transactions as part of its investment strategies and may increase the cost of the Funds’ investments and cost of doing business, which could adversely affect investors. The compliance date for the new rule and related reporting requirements was August 19, 2022.

In December 2020, the SEC adopted a rule addressing fair valuation of fund investments. The new rule sets forth requirements for good faith determinations of fair value as well as for the performance of fair value determinations, including related oversight and reporting obligations. The new rule also defines “readily available market quotations” for purposes of the definition of “value” under the Investment Company Act of 1940 (the “Act”), and the SEC noted that this definition will apply in all contexts under the Act.

In May 2022, the SEC proposed amendments to a current rule governing fund naming conventions. In general, the current rule requires funds with certain types of names to adopt a policy to invest at least 80% of their assets in the type of investment suggested by the name. The proposed amendments would expand the scope of the current rule in a number of ways that would result in an expansion of the types of fund names that would require the fund to adopt an 80% investment policy under the rule. Additionally, the proposed amendments would modify the circumstances under which a fund may deviate from its 80% investment policy and address the use and valuation of derivatives instruments for purposes of the rule. The proposal’s impact on the Funds will not be known unless and until any final rulemaking is adopted.

In May 2022, the SEC proposed a framework that would require certain registered funds (such as the Funds) to disclose their environmental, social, and governance (“ESG”) investing practices. Among other things, the proposed requirements would mandate that funds meeting three pre-defined classifications (i.e., integrated, ESG focused and/or impact funds) provide prospectus and shareholder report disclosure related to the ESG factors, criteria and processes used in managing the fund. The proposal’s impact on the Funds will not be known unless and until any final rulemaking is adopted.

In October 2022, the SEC adopted changes to the mutual fund and exchange-traded fund (“ETF”) shareholder report and registration statement disclosure requirements and the registered fund advertising rules, which will impact the disclosures provided to shareholders. The rule amendments are effective as of January 24, 2023, but the SEC is providing an 18-month compliance period following the effective date for such amendments other than those addressing fee and expense information in advertisements that might be materially misleading.

In November 2022, the SEC adopted amendments to Form N-PX under the Act to improve the utility to investors of proxy voting information reported by mutual funds, ETFs and certain other funds. The rule amendments will expand the scope of funds’ Form N-PX reporting obligations, subject managers to Form N-PX reporting obligations for “Say on Pay” votes, enhance Form N-PX disclosures, permit joint reporting by funds, managers and affiliated managers on Form N-PX; and require website availability of fund proxy voting records. The amendments will become effective on July 1, 2024. Funds and managers will be required to file their first reports covering the period from July 1, 2023 to June 30, 2024 on amended Form N-PX by August 31, 2024.

In May 2023, the SEC adopted final amendments that will require increased disclosure regarding repurchases by issuers of their equity securities registered under Section 12 of the Securities Exchange Act of 1934, as amended. The final amendments apply to business development

companies and listed closed-end funds, but they do not apply to open-end funds or unlisted closed-end funds. Business development companies and listed closed-end funds will be required to provide greater quantitative and qualitative details related to share repurchases in their periodic reports, including: (i) daily quantitative share repurchase data presented in a table attached as an exhibit to the issuer’s periodic reports; (ii) checkbox disclosure regarding whether its directors and officers purchased or sold shares that are the subject of the issuer’s repurchase plan or program within four business days before or after the issuer’s announcement of such repurchase plan or program or the announcement of an increase of an existing share repurchase plan or program; and (iii) narrative descriptions regarding the issuer’s repurchase programs and practices. Listed closed-end funds are required to comply with the new requirements beginning with the Form N-CSR that covers the first six-month period that begins on or after January 1, 2024.

PIMCO California Flexible Municipal Income Fund

Cumulative Returns Through June 30, 2023

$10,000 invested at the end of the month when the Fund’s Institutional Class commenced operations

Average Annual Total Return for the period ended June 30, 2023
				6 Months*				1 Year				Commencement of Operations**
		PIMCO California Flexible Municipal Income Fund Institutional Class			4.09%				3.58%				3.96%
		PIMCO California Flexible Municipal Income Fund Class A-1			3.84%				3.07%				3.45%
		Bloomberg CA Muni 22+ Year Index			4.38%				4.71%				5.45%

All Fund returns are net of fees and expenses and include applicable fee waivers and/or expense limitations. Absent any applicable fee waivers and/or expense limitations, performance would have been lower and there can be no assurance that any such waivers or limitations will continue in the future.

It is not possible to invest directly in an unmanaged index.

Performance quoted represents past performance. Past performance is not a guarantee or a reliable indicator of future results. Current performance may be lower or higher than performance shown. Investment return and the principal value of an investment will fluctuate. Shares may be worth more or less than original cost when redeemed. Returns shown do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. Performance current to the most recent month-end is available at www.pimco.com or via (844) 312-2113. Performance is calculated assuming all dividends and distributions are reinvested at prices obtained under the Fund’s dividend reinvestment plan. Performance does not reflect brokerage commissions in connection with the purchase or sale of Fund shares.

Performance of an index is shown in light of a requirement by the Securities and Exchange Commission that the performance of an appropriate broad-based securities market index be disclosed. However, the Fund is not managed to an index nor should the index be viewed as a “benchmark” for the Fund’s performance. The index is not intended to be indicative of the Fund’s investment strategies, portfolio components or past or future performance.

For periods prior to the inception date of the Class A-1 shares, performance information shown is based on the performance of the Fund’s Institutional Class shares. The prior Institutional Class performance has been adjusted to reflect the distribution and/or service fees and other expenses paid by the Class A-1 shares.

The Fund’s total annual operating expense ratio, as stated in the Fund’s currently-effective prospectus (as of the date of this report), were 1.93% for Institutional Class shares and 2.43% for Class A-1 shares. See Financial Highlights for actual expense ratios as of the end of the period covered by this report.

PIMCO California Flexible Municipal Income Fund (Cont.)

Investment Objective and Strategy Overview

PIMCO California Flexible Municipal Income Fund’s investment objective is to seek high current income exempt from federal and California income tax by investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in a portfolio of municipal bonds and other municipal securities, the interest from which, in the opinion of bond counsel for the issuer at the time of issuance (or on the basis of other authority believed by PIMCO to be reliable), is exempt from federal income tax and California income tax (i.e., excluded from gross income for income tax purposes but not necessarily exempt from the alternative minimum tax or from the income taxes of any other state or of a local government). Capital appreciation is a secondary objective. Fund strategies may change from time to time. Please refer to the Fund’s current prospectus for more information regarding the Fund’s strategy.

Fund Insights at NAV

The following affected performance (on a gross basis) during the reporting period:

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PIMCO Flexible Municipal Income Fund

Cumulative Returns Through June 30, 2023

$10,000 invested at the end of the month when the Fund’s Institutional Class commenced operations

Average Annual Total Return for the period ended June 30, 2023
				6 Months*				1 Year				Commencement of Operations**
		PIMCO Flexible Municipal Income Fund Institutional Class			4.48%				4.33%				3.42%
		PIMCO Flexible Municipal Income Fund Class A-1			4.21%				3.80%				2.83%
		PIMCO Flexible Municipal Income Fund Class A-2			4.22%				3.81%				2.82%
		PIMCO Flexible Municipal Income Fund Class A-2 (adjusted)			2.13%				1.77%				2.34%
		PIMCO Flexible Municipal Income Fund Class A-3			4.08%				3.53%				2.64%
		Bloomberg Long Municipal Bond Index			4.96%				3.84%				1.10%

All Fund returns are net of fees and expenses and include applicable fee waivers and/or expense limitations. Absent any applicable fee waivers and/or expense limitations, performance would have been lower and there can be no assurance that any such waivers or limitations will continue in the future.

It is not possible to invest directly in an unmanaged index.

Performance quoted represents past performance. Past performance is not a guarantee or a reliable indicator of future results. Current performance may be lower or higher than performance shown. Investment return and the principal value of an investment will fluctuate. Shares may be worth more or less than original cost when redeemed. Returns shown do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. The adjusted returns take into account the maximum sales charge of 3.00% on Class A-2. Performance current to the most recent month-end is available at www.pimco.com or via (844) 312-2113. Performance is calculated assuming all dividends and distributions are reinvested at prices obtained under the Fund’s dividend reinvestment plan. Performance does not reflect brokerage commissions in connection with the purchase or sale of Fund shares.

Performance of an index is shown in light of a requirement by the Securities and Exchange Commission that the performance of an appropriate broad-based securities market index be disclosed. However, the Fund is not managed to an index nor should the index be viewed as a “benchmark” for the Fund’s performance. The index is not intended to be indicative of the Fund’s investment strategies, portfolio components or past or future performance.

For periods prior to the inception date of the Class A-1, Class A-2 and Class A-3 shares performance information shown is based on the performance of the Fund’s Institutional Class shares. The prior Institutional Class performance has been adjusted to reflect the distribution and/or service fees and other expenses paid by the Class A-1, Class A-2 and Class A-3 shares.

The Fund’s total annual operating expense ratio, as stated in the Fund’s currently-effective prospectus (as of the date of this report), which include the Acquired Fund Fees and Expenses, were 2.60% for Institutional Class, 3.10% for Class A-1 shares, 3.10% for Class A-2 shares and 3.35% for Class A-3 shares. As of June 30, 2023, the Fund’s Total Effective Leverage⁽¹⁾ was 22.66%. See Financial Highlights for actual expense ratios as of the end of the period covered by this report.

PIMCO Flexible Municipal Income Fund (Cont.)

Investment Objective and Strategy Overview

PIMCO Flexible Municipal Income Fund seeks to provide high current income exempt from federal income tax. Capital appreciation is a secondary objective. The Fund attempts to achieve these objectives by investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in a portfolio of municipal bonds and other municipal securities, the interest from which, in the opinion of bond counsel for the issuer at the time of issuance (or on the basis of other authority believed by PIMCO to be reliable), is exempt from federal income tax. Fund strategies may change from time to time. Please refer to the Fund’s current prospectus for more information regarding the Fund’s strategy.

Fund Insights at NAV

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Financial Highlights

Financial Highlights (Cont.)

Ratios/Supplemental Data

Statements of Assets and Liabilities

(Unaudited)

June 30, 2023

Statements of Operations

Statements of Changes in Net Assets