PIMCO Dynamic Income Fund (PDI) N-CSRSCertified semi-annual shareholder report (management investment company)

floating interest rate) with respect to a contract whereby the payment obligations do not commence until a date following the commencement of the initial leg (the “forward leg”).

A Fund may engage in investment strategies, including those that employ the use of paired swaps transactions, the use of interest rate swaps to seek to capitalize on differences between short-term and long-term interest rates and other derivatives transactions, to, among other things, seek to generate current, distributable income, even if such strategies could potentially result in declines in the Fund’s net asset value (“NAV”). A Fund’s income and gain-generating strategies, including certain derivatives strategies, may generate current income and gains taxable as ordinary income sufficient to support monthly distributions even in situations when a Fund has experienced a decline in net assets due to, for example, adverse changes in the broad U.S. or non-U.S. equity markets or a Fund’s debt investments, or arising from its use of derivatives. For instance, a portion of a Fund’s monthly distributions may be sourced from paired swap transactions utilized to produce current distributable ordinary income for tax purposes on the initial leg, with a substantial possibility that a Fund will later realize a corresponding capital loss and potential decline in its NAV with respect to the forward leg (to the extent there are not corresponding offsetting capital gains being generated from other sources). Because some or all of these transactions may generate capital losses without corresponding offsetting capital gains, portions of a Fund’s distributions recognized as ordinary income for tax purposes (such as from paired swap transactions) may be economically similar to a taxable return of capital when considered together with such capital losses.

The use of derivatives may subject the Funds to greater volatility than investments in traditional securities. The Funds may use derivative instruments for hedging purposes or as part of an investment strategy. Use of these instruments may involve certain costs and risks such as liquidity risk (which may be heightened for highly-customized derivatives), interest rate risk, market risk, credit risk and management risk, as well as risks arising from changes in applicable requirements. They also involve the risk of improper valuation and the risk that changes in the value of a derivative instrument may not correlate perfectly with the underlying asset, rate or index.

rate of return on a Fund’s portfolio, the interest and other costs of leverage to the Fund could exceed the rate of return on the debt obligations and other investments held by the Fund, thereby reducing return to the Fund’s common shareholders. In addition, fees and expenses of any form of leverage used by a Fund will be borne entirely by its common shareholders (and not by preferred shareholders, if any) and will reduce the investment return of the Fund’s common shares. Moreover, to make payments of interest and other loan costs, a Fund may be forced to sell portfolio securities when it is not otherwise advantageous to do so. In addition, because the fees received by PIMCO are based on the total managed assets or the daily NAV of a Fund (including any assets attributable to certain types of leverage outstanding), as applicable, PIMCO has a financial incentive for the Funds to use certain forms of leverage, which may create a conflict of interest between PIMCO, on the one hand, and the Funds’ common shareholders, on the other hand.

There can be no assurance that a Fund’s use of leverage will result in a higher yield on its common shares, and it may result in losses. Leverage creates several major types of risks for a Fund’s common shareholders, including (1) the likelihood of greater volatility of NAV and market price of the Fund’s common shares, and of the investment return to the Fund’s common shareholders, than a comparable portfolio without leverage; (2) the possibility either that the Fund’s common share dividends will fall if the interest and other costs of leverage rise, or that dividends paid on the Fund’s common shares will fluctuate because such costs vary over time; and (3) the effects of leverage in a declining market or a rising interest rate environment, as leverage is likely to cause a greater decline in the NAV of the Fund’s common shares than if the Fund were not leveraged and may result in a greater decline in the market value of the Fund’s common shares.

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 Schedule of Investments or Consolidated Schedule of Investments, as applicable, 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.

Investments in loans through a purchase of a loan or a direct assignment of a financial institution’s interests with respect to a loan are generally subject to risks similar to those of investments in other types of debt obligations, including, among others, credit risk, interest rate risk, variable and floating rate securities risk, and, as applicable, risks associated with mortgage-related securities. In addition, in many cases loans are subject to the risks associated with below-investment grade securities.

sensitive to changes in interest rates. As a result, in a period of rising interest rates, if a Fund holds mortgage-related securities, it may exhibit additional volatility since individual mortgage holders are less likely to exercise prepayment options, thereby putting additional downward pressure on the value of these securities and potentially causing the Fund to lose money. The Funds’ investments in other asset-backed instruments are subject to risks similar to those associated with mortgage-related assets, as well as additional risks associated with the nature of the assets and the servicing of those assets. Payment of principal and interest on asset-backed securities may be largely dependent upon the cash flows generated by the assets backing the securities, and asset-backed securities may not have the benefit of any security interest in the related assets. Additionally, investments in subordinate mortgage-backed and other asset-backed instruments will be subject to risks arising from delinquencies and foreclosures, thereby exposing a Fund’s investment portfolio to potential losses. Subordinate securities of mortgage-backed and other asset-backed instruments are also subject to greater credit risk than those mortgage-backed or other asset-backed securities that are more highly rated.

A Fund may also invest in the residual or equity tranches of mortgage-related and other asset-backed instruments, which may be referred to as subordinate mortgage-backed or asset-backed instruments and interest-only mortgage-backed or asset-backed instruments. Because an investment in the residual or equity tranche of a mortgage-related or other asset-backed instrument will be the first to bear losses incurred by such instrument, these investments may involve a significantly greater degree of risk than investments in other tranches of a mortgage-related or other asset-backed instruments.

High-yield bonds (commonly referred to as “junk bonds”) typically have a lower credit rating than other bonds. Lower-rated bonds generally involve a greater risk to principal than higher-rated bonds. Further, markets for lower-rated bonds are typically less liquid than for higher rated bonds, and public information is usually less abundant in markets for lower-rated bonds. Thus, high yield investments increase the chance that a Fund will lose money. PIMCO does not rely solely on credit ratings, and develops its own analysis of issuer credit quality. A Fund may purchase unrated securities (which are not rated by a rating agency) if PIMCO determines that the security is of comparable quality to a rated security that a Fund may purchase. Unrated securities may be less liquid than comparable rated securities and involve the risk that PIMCO may not accurately evaluate the security’s comparative credit quality, which could result in a Fund’s portfolio having a higher level of credit and/or high yield risk than PIMCO has estimated or desires for the Fund, and could negatively impact the Fund’s performance and/or returns. Certain Funds may invest a substantial portion of their assets in unrated securities and therefore may be particularly subject to the associated risks. To the extent that a Fund invests in high yield and/or unrated securities, the Fund’s success in achieving its investment objectives may depend more heavily on the portfolio manager’s creditworthiness analysis than if the Fund invested exclusively in

receive principal and interest payments due on fractions of whole loans or pools of whole loans, or any other security or other instrument that the parent Fund may hold directly. References herein to a Fund include references to a Subsidiary in respect of the Fund’s investment exposure. The allocation of a Fund’s portfolio in a Subsidiary will vary over time and might not always include all of the different types of investments described herein. By investing through its Subsidiaries, a Fund is exposed to the risks associated with the Subsidiaries’ investments. The Subsidiaries are not registered as investment companies under the Investment Company Act of 1940, as amended, and the rules and regulations thereunder (the “Act”) and are not subject to all of the investor protections of the Act, although each Subsidiary is managed pursuant to the compliance policies and procedures of the Fund applicable to it. Changes in the laws of the United States and/or the jurisdiction in which a Subsidiary is organized could result in the inability of certain Funds and/or their Subsidiaries to operate as described in this report and could adversely affect the Funds.

Certain Funds may acquire residential mortgage loans and unsecured consumer loans through a Subsidiary. Subsidiaries directly holding a beneficial interest in loans will be formed as domestic common law or statutory trusts with a federally chartered bank serving as trustee. Each such Subsidiary will hold the beneficial interests of loans and the federally chartered bank acting as trustee will hold legal title to the loans for the benefit of the Subsidiary and/or the trust’s beneficial owners (i.e., a Fund or its Subsidiary). State licensing laws typically exempt federally chartered banks from their licensing requirements, and federally chartered banks may also benefit from federal preemption of state laws, including any licensing requirements. The use of common law or statutory trusts with a federally chartered bank serving as trustee is intended to address any state licensing requirements that may be applicable to purchasers or holders of loans, including state licensing requirements related to foreclosure. The Funds believe that such Subsidiaries will not be treated as associations or publicly traded partnerships taxable as corporations for U.S. federal income tax purposes, and that therefore, the Subsidiaries will not be subject to U.S. federal income tax at the subsidiary level. Investments in residential mortgage loans or unsecured consumer loans through entities that are not so treated can potentially be limited by a Fund’s intention to qualify as a regulated investment company, and limit the Fund’s ability to qualify as such.

If a Fund or its Subsidiary is required to be licensed in any particular jurisdiction in order to acquire, hold, dispose or foreclose loans, obtaining the required license may not be viable (because, for example, it is not possible or practical) and the Fund or its Subsidiary may be unable to restructure its holdings to address the licensing requirement. In that case, a Fund or its Subsidiary may be forced to cease activities involving the affected loans, or may be forced to sell such loans. If a state regulator or court were to determine that a Fund or its Subsidiary acquired, held or foreclosed a loan without a required state license, the Fund or its Subsidiary could be subject to penalties or other sanctions,

foreign exchange markets, lead to weakness in the exchange rate of the British pound, result in a sustained period of market uncertainty, and destabilize some or all of the other European Union member countries and/or the Eurozone.

The Funds may invest in certain instruments that rely in some fashion upon the London Interbank Offered Rate (“LIBOR”). LIBOR is an average interest rate, determined by the ICE Benchmark Administration, that banks charge one another for the use of short-term money. The United Kingdom’s Financial Conduct Authority, which regulates LIBOR, has announced plans to ultimately phase out the use of LIBOR. The transition may 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. There remains uncertainty regarding future utilization of LIBOR and the nature of any replacement rate (e.g., the Secured Overnight Financing Rate, which is intended to replace U.S. dollar LIBOR and measures the cost of overnight borrowings through repurchase agreement transactions collateralized with U.S. Treasury securities). Any potential effects of the transition away from LIBOR on a Fund or on certain instruments in which a Fund invests can be difficult to ascertain, and they may vary depending on a variety of factors. Any such effects of the transition away from LIBOR, as well as other unforeseen effects, could result in losses to a Fund.

The common shares of the Funds trade on the New York Stock Exchange. As with any stock, the price of a Fund’s common shares will fluctuate with market conditions and other factors. If you sell your common shares of a Fund, the price received may be more or less than your original investment. Shares of closed-end management investment companies, such as the Funds, frequently trade at a discount from their NAV and may trade at a price that is less than the initial offering price and/or the NAV of such shares. Further, if a Fund’s shares trade at a price that is more than the initial offering price and/or the NAV of such shares, including at a substantial premium and/or for an extended period of time, there is no assurance that any such premium will be sustained for any period of time and will not decrease, or that the shares will not trade at a discount to NAV thereafter.

The Funds may be subject to various risks. A description of certain of these risks is available in the Notes to Financial Statements of this report.

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 or market price (as applicable) in the specified period. Returns do not reflect the deduction of taxes that a shareholder would pay on Fund distributions. Total return for a period of more than one year represents the average annual total return. Performance at market price will differ from results at NAV. Although market price returns tend to reflect investment results over time, during shorter periods returns at market price can also be influenced by factors such as changing views

The Trustees (or the Funds and their 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 a Fund, 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 any 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 a Fund’s then-current 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) 33‑PIMCO, 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 portfolio holdings information with the SEC on Form N‑PORT within 60 days of the end of each fiscal quarter. The Funds’ complete schedules of securities holdings as of the end of each fiscal quarter will be made available to the public on the SEC’s website at www.sec.gov and on PIMCO’s website at www.pimco.com, and will be made available, upon request, by calling PIMCO at (844) 33-PIMCO.

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) 33-PIMCO. Any election to receive reports in paper will apply to all funds held with the 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

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.