PIMCO EMERGING MARKETS CORPORATE BOND FUND

PIMCO Emerging Markets Corporate Bond Fund

Summary Prospectus

August 1, 2025

Share Class:	Inst
Ticker:	PEMIX

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 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@sscinc.com. The Fund’s prospectus and Statement of Additional Information, both dated August 1, 2025, as supplemented, are incorporated by reference into this Summary Prospectus.

Investment Objective

The Fund seeks maximum total return, consistent with preservation of capital and prudent investment management.

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.

Shareholder Fees (fees paid directly from your investment):

None

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

	Inst Class
Management Fees	0.85%
Distribution and/or Service (12b-1) Fees	N/A
Other Expenses(1)	0.18%
Total Annual Fund Operating Expenses(2)	1.03%

“Other Expenses” include interest expense of 0.18%. Interest expense is borne by the Fund separately from the management fees paid to Pacific Investment Management Company LLC (“PIMCO”). Excluding interest expense, Total Annual Fund Operating Expenses are 0.85% for Institutional Class.

Total Annual Fund Operating Expenses have been restated to reflect current expenses

Example. The Example is intended to help you compare the cost of investing in Institutional Class 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:

	1 Year	3 Years	5 Years	10 Years
Institutional Class	$105	$328	$569	$1,259

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 96% of the average value of its portfolio.

Principal Investment Strategies

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its assets in a diversified portfolio of corporate Fixed Income Instruments that are economically tied to emerging market countries, which may be represented by forwards or derivatives such as options, futures contracts or swap agreements. “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. Such instruments may be denominated in non-U.S. currencies and the U.S. dollar. The average portfolio duration of this Fund normally varies within two years (plus or minus) of the portfolio duration of the securities comprising the JPMorgan Corporate Emerging Markets Bond Index Diversified (CEMBI), as calculated by PIMCO, which as of May 31, 2025 was 3.98 years. Duration is a measure used to determine the sensitivity of a security’s price to changes in interest rates. The longer a security’s duration, the more sensitive it will be to changes in interest rates.

PIMCO has broad discretion to identify countries that it considers to qualify as emerging markets. The Fund emphasizes countries with relatively low gross national product per capita and with the potential for rapid economic growth. PIMCO will select the Fund’s country and currency composition based on its evaluation of relative interest rates, inflation rates, exchange rates, monetary and fiscal policies, trade and current account balances, legal and political developments, and any other specific factors PIMCO believes to be relevant. The Fund likely will focus its investments in Asia, Africa, the Middle East, Latin America and the developing countries of Europe. The Fund may invest in instruments whose return is based on the return of an emerging market security or a currency of an emerging market country, such as a derivative instrument, rather than investing directly in emerging market securities or currencies.

The Fund may invest in both investment-grade securities and high yield securities (“junk bonds”) subject to a maximum of 15% of its total assets in securities rated below B by Moody’s Ratings (“Moody’s”), or equivalently rated by Standard & Poor’s Ratings Services (“S&P”) or Fitch Ratings, Inc. (“Fitch”), or, if unrated, determined by PIMCO to be of comparable quality. In the event that ratings services assign different ratings to the same security, PIMCO will use the highest rating as the credit rating for that security.

The Fund may invest, without limitation, in derivative instruments, such as options, futures contracts or swap agreements, or in mortgage- or asset-backed securities, subject to applicable law and any other

PIMCO Funds | Summary Prospectus

PIMCO Emerging Markets Corporate Bond Fund

restrictions described in the Fund’s prospectus or Statement of Additional Information. The Fund may purchase or sell securities on a when-issued, delayed delivery or forward commitment basis and may engage in short sales. The Fund may also invest directly in real estate investment trusts (“REITs”). The Fund may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as buy backs or dollar rolls). The “total return” sought by the Fund consists of income earned on the Fund’s investments, plus capital appreciation, if any, which generally arises from decreases in interest rates, foreign currency appreciation, or improving credit fundamentals for a particular sector or security.

Principal Risks

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below

Small Fund Risk: the risk that a smaller fund may not achieve investment or trading efficiencies or may be limited in ability to participate in certain investment opportunities due to its size. Additionally, a smaller fund may be more adversely affected by large purchases or redemptions by investors

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. Factors such as government policy, inflation, the economy, and market for bonds can impact interest rates and yields

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 including 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 experience losses 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 Risk: the risk that high yield securities and unrated securities of similar credit quality (commonly known as “junk bonds”) are subject to greater levels of market, credit, call and liquidity risks. High yield securities are considered primarily speculative by rating agencies with respect to the issuer’s continuing ability to make principal and interest payments, and their values may be more volatile than higher-rated securities of similar maturity

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 reasons 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 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

Derivatives Risk: the risk of investing in derivative instruments (such as forwards, futures, options, 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

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 Fund’s guidelines), which generally carry higher levels of the foregoing risks

2 Summary Prospectus | PIMCO Funds

Summary Prospectus

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, corporate governance and auditing standards, increased risk of delayed settlement of portfolio transactions or loss of certificates of portfolio securities, and the risk of unfavorable U.S. or foreign government actions, including nationalization, expropriation or confiscatory taxation, currency blockage, political changes, diplomatic developments, trade restrictions (including tariffs) 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 risks related to losses from casualty or condemnation, 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, REITs that are privately held or not traded on a national securities exchange may 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

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. The use of leverage may also increase the Fund’s sensitivity to interest rate risks

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

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

Contingent Convertible Securities Risk: the risks of investing in contingent convertible securities, including the risk that interest payments will be cancelled by the issuer or a regulatory authority, the risk of ranking junior to other creditors in the event of a liquidation or other bankruptcy- related event as a result of holding subordinated debt, the risk of the Fund’s investment becoming further subordinated as a result of conversion from debt to equity, the risk of the Fund's investment receiving less favorable treatment than equity of the issuer in certain situations, such as during financial distress or regulatory intervention, the risk that principal amount due can be written down to a lesser amount (including potentially to zero), and the general risks applicable to fixed income investments, including interest rate risk, credit risk, market risk and liquidity risk, any of which 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 expense limitations, performance would have been lower. The bar chart shows performance of the Fund’s Institutional Class shares. 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. The Fund’s regulatory index is the Bloomberg Global Aggregate (USD Hedged) Index. The Fund’s regulatory index is shown in connection with certain regulatory requirements to provide a broad measure of market performance. The Bloomberg Global Aggregate (USD Hedged) Index provides a broad-based measure of the global investment-grade fixed income markets. The three major components of this index are the U.S. Aggregate, the Pan-European Aggregate, and the Asian-Pacific Aggregate Indices. The index also includes Eurodollar and Euro-Yen corporate bonds, Canadian Government securities, and USD investment grade 144A securities. The supplemental index shown is the J.P. Morgan

August 1, 2025 | SUMMARY PROSPECTUS 3

PIMCO Emerging Markets Corporate Bond Fund

Corporate Emerging Markets Bond Index Diversified (CEMBI). The index is a uniquely weighted version of the CEMBI index. It limits the weights of those index countries with larger corporate debt stocks by only including a specified portion of these countries’ eligible current face amounts of debt outstanding. The CEMBI Diversified results in well-distributed, more balanced weightings for countries included in the index. The countries covered in the CEMBI Diversified are identical to those covered by the CEMBI.

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	12.21%
Worst Quarter	March 31, 2020	-12.17%
Year-to-Date	June 30, 2025	4.73%

Average Annual Total Returns (for periods ended 12/31/24)

	1 Year	5 Years	10 Years
Institutional Class Return Before Taxes	6.30%	0.67%	2.97%
Institutional Class Return After Taxes on Distributions(1)	3.98%	-1.08%	1.06%
Institutional Class Return After Taxes on Distributions and Sales of Fund Shares(1)	3.71%	-0.24%	1.43%
Bloomberg Global Aggregate (USD Hedged) Index (reflects no deductions for fees, expenses or taxes)	3.40%	0.48%	2.01%
J.P. Morgan Corporate Emerging Markets Bond Index Diversified (CEMBI) (reflects no deductions for fees, expenses or taxes)	7.34%	1.82%	3.94%

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.

Investment Adviser/Portfolio Managers

PIMCO serves as the investment adviser for the Fund. The Fund’s portfolio is jointly and primarily managed by Mohit Mittal, Yacov Arnopolin, Michal Bar and Abhijeet Neogy. Mr. Mittal is CIO Core Strategies and a Managing Director of PIMCO, Mr. Arnopolin is a Managing Director of PIMCO, Ms. Bar is an Executive Vice President of PIMCO and Mr. Neogy is a Senior Vice President of PIMCO. Messrs. Mittal and Arnopolin have managed the Fund since December 2016, Ms. Bar has managed the Fund since October 2020, and Mr. Neogy has managed the Fund since August 2024.

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

The minimum initial investment for Institutional 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 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.

801 Pennsylvania Avenue, STE 219024, Kansas City, MO 64105-1307

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Calling us at 1.888.87.PIMCO and a Shareholder Services associate will assist you

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Sending a fax to our Shareholder Services department at 816.421.2861

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Sending an e-mail to piprocess@sscinc.com

4 Summary Prospectus | PIMCO Funds