497
PIMCO Funds
Prospectus
July 31, 2023 (as supplemented September 29, 2023)
Bond Funds
 
Inst
I-2
I-3
Admin
A
C
R
PIMCO Climate Bond Fund
PCEIX
PCEPX
PCEWX
PCEBX
PCECX
PIMCO Dynamic Bond Fund
PFIUX
PUCPX
PFNUX
PUBAX
PUBCX
PUBRX
PIMCO Extended Duration Fund
PEDIX
PEDPX
PIMCO GNMA and Government
Securities Fund
PDMIX
PPGNX
PANNX
PAGNX
PCGNX
PIMCO Investment Grade Credit Bond
Fund
PIGIX
PBDPX
PCNNX
PGCAX
PBDAX
PBDCX
PIMCO Long Duration Total Return
Fund
PLRIX
PLRPX
PLRAX
PLRCX
PIMCO Long-Term U.S. Government
Fund
PGOVX
PLTPX
PFGAX
PFGCX
PIMCO Low Duration Opportunities
Fund
PUTIX
PUTPX
ATMAX
ATMCX
PIMCO Moderate Duration Fund
PMDRX
PMOPX
PIMCO Mortgage-Backed Securities
Fund
PTRIX
PMRPX
PSANX
PMRAX
PMRCX
PIMCO Mortgage Opportunities and
Bond Fund
PMZIX
PMZPX
PMZNX
PMZAX
PMZCX
PIMCO Total Return Fund
PTTRX
PTTPX
PTTNX
PTRAX
PTTAX
PTTCX
PTRRX
PIMCO Total Return Fund II
PMBIX
PMTPX
PIMCO Total Return Fund IV
PTUIX
PTUZX
PIMCO Total Return Fund V
PPEIX
PIMCO Total Return ESG Fund
PTSAX
PRAPX
PTRSX
PRFAX
PTGAX
PTGCX
Neither the U.S. Securities and Exchange Commission nor the U.S. Commodity Futures Trading Commission has approved or disapproved these securities, or determined if this prospectus is truthfuI or compIete. Any representation to the contrary is a criminaI offense.

Table of Contents
 
Page
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48
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65
70
71
84
85
91
98
106
107
108
109
128
A-1
B-1


PIMCO Climate Bond Fund

Investment Objective
The Fund seeks optimal risk adjusted returns, consistent with prudent investment management, while giving consideration to long term climate related risks and opportunities.
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 91 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
Class A
Class C
Maximum Sales Charge (Load) Imposed on
Purchases (as a percentage of offering price)
None
None
None
2.25%
None
Maximum Deferred Sales Charge (Load) (as a
percentage of the lower of the original purchase
price or redemption price)
None
None
None
1.00%
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
Class A
Class C
Management Fees
0.50%
0.60%
0.70%
0.65%
0.65%
Distribution and/or Service (12b-1) Fees
N/A
N/A
N/A
0.25%
1.00%
Other Expenses(1)
0.09%
0.09%
0.09%
0.09%
0.09%
Total Annual Fund Operating Expenses
0.59%
0.69%
0.79%
0.99%
1.74%
Fee Waiver and/or Expense Reimbursement(2)
N/A
N/A
(0.05%)
N/A
N/A
Total Annual Fund Operating Expenses
After Fee Waiver and/or Expense
Reimbursement
0.59%
0.69%
0.74%
0.99%
1.74%
1
“Other Expenses” include interest expense of 0.08%. 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 After Fee Waiver and/or Expense Reimbursement are 0.51%, 0.61%, 0.66%, 0.91% and 1.66% for Institutional Class, I-2, I-3, Class A and Class C shares, respectively.
2
PIMCO has contractually agreed, through July 31, 2024, 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.
Example.The Example is intended to help you compare the cost of investing in Institutional Class, I-2, I-3, Class A or Class C 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
$60
$189
$329
$738
I-2
$70
$221
$384
$859
I-3
$76
$247
$434
$973
Class A
$324
$533
$760
$1,411
Class C
$277
$548
$944
$2,052
If you do not redeem your shares:
 
1 Year
3 Years
5 Years
10 Years
Class A
$324
$533
$760
$1,411
Class C
$177
$548
$944
$2,052
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 38% 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 Fixed Income Instruments of varying maturities, 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. The average portfolio duration of this Fund will normally vary from 2 years to 8 years based on PIMCO’s market forecasts. 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.
The Fund invests opportunistically in a broad spectrum of climate focused instruments and debt from issuers demonstrating leadership with respect to addressing climate related factors. Given the long term nature of the risks and opportunities presented by climate change and resource depletion, PIMCO may emphasize investment strategies that are more strategic, or long-term in nature, with less emphasis on short-term, tactical trading strategies.
The Fund’s investments ordinarily include labeled and unlabeled “green” bonds, as well as the debt of issuers demonstrating leadership in addressing risk and opportunities around climate related change. Labeled green bonds are those issues with proceeds specifically

PIMCO Funds | Prospectus  1

PIMCO Climate Bond Fund

earmarked to be used for climate and environmental projects. Labeled green bonds are often verified by a third party, which certifies that the bond will fund projects that include environmental benefits. Unlabeled green bonds or climate-aligned bonds are securities of climate-aligned issuers with use of proceeds for climate-related projects and initiatives, and may be issued without formal third party verifications or frameworks. When considering whether an issuer has demonstrated leadership in addressing risk and opportunities around climate related change, PIMCO may consider a variety of factors, such as whether an issuer provides low carbon solutions, has implemented or prepared a transition plan to a low carbon economy or such other factors that PIMCO may determine are relevant.
When considering an investment, PIMCO may utilize the following resources, among others, to evaluate climate related factors: PIMCO’s internal research and scoring process relating to climate factors, third party research and data providers, an issuer’s alignment with international commitments deemed relevant by PIMCO (such as the 2016 Paris Agreement on climate change), and/or information made available by the issuer, such as carbon emissions and intensity. In determining the efficacy of an issuer’s environmental practices, PIMCO will use its own proprietary assessments of material environmental and climate-oriented issues and may also reference standards as set forth by recognized global organizations, such as entities sponsored by the United Nations.
The Fund may avoid investment in the securities of issuers whose business practices with respect to climate specific factors do not meet criteria established by PIMCO. Additionally, PIMCO may engage proactively with issuers to encourage them to improve their environmental practices or preparations for a low carbon economy. PIMCO’s activities in this respect may include, but are not limited to, direct dialogue with company management, such as through in-person meetings, phone calls, electronic communications and letters. Through these engagement activities, PIMCO will seek to identify opportunities for a company to improve its climate focused practices and will endeavor to work collaboratively with company management to establish concrete objectives and to develop a plan for meeting these objectives. The Fund has flexibility to invest in securities of issuers whose climate-related practices are currently suboptimal, with the expectation that these practices may improve over time either as a result of PIMCO’s engagement efforts or through the company’s own initiatives. The Fund may exclude those issuers that are not receptive to PIMCO’s engagement efforts, as determined in PIMCO’s sole discretion.
The Fund will not invest in the securities of any issuer determined by PIMCO to be engaged principally in the fossil fuel-related sectors, including distribution/retail, equipment and services, extraction and production, petrochemicals, pipelines and transportation and refining, and the production or distribution of coal and coal fired generation. The Fund may invest in the securities of issuers determined by PIMCO to be engaged principally in biofuel production, natural gas generation and sales and trading activities. Moreover, the Fund will not invest in the securities of any issuer determined by PIMCO to be engaged principally in the manufacture of alcoholic beverages, tobacco products or military
equipment, the operation of gambling casinos, or in the production or trade of pornographic materials. To the extent possible on the basis of information available to PIMCO, an issuer will be deemed to be principally engaged in an activity if it derives more than 10% of its gross revenues from such activities. The Fund may invest in labeled green, sustainability, social and sustainability-linked bonds from issuers involved in fossil fuel-related sectors. Labeled bonds are those issues with proceeds specifically earmarked to be used for climate, environmental sustainability and/or social projects and, in the case of sustainability-linked bonds, bonds that include sustainability-linked covenants, as explained by the issuer through use of a framework and/or legal documentation. Labeled bonds are often verified by a third party, which certifies that the bond will or has been used to fund projects that include eligible benefits or, in the case of a sustainability-linked bond, that the bond includes sustainability-linked covenants.
The Fund may invest in up to 25% of its total assets in high yield securities (“junk bonds”), as rated by Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor’s Ratings Services (“S&P”) or Fitch, Inc. (“Fitch”), or, if unrated, determined by PIMCO (except such limitation shall not apply to the Fund’s investments in mortgage- and asset-backed securities). In the event that ratings and services assign different ratings to the same security, PIMCO will use the highest rating as the credit rating for that security. The Fund may also invest without limitation in securities denominated in foreign currencies and in U.S. dollar-denominated securities of foreign issuers. In addition, the Fund may invest up to 25% of its total assets in securities and instruments that are economically tied to emerging market countries (this limitation does not apply to investment grade sovereign debt denominated in the local currency with less than 1 year remaining to maturity, which means the Fund may invest in such instruments without limitation subject to any applicable legal or regulatory limitation). The Fund will normally limit its foreign currency exposure (from non-U.S. dollar-denominated securities or currencies) to 20% of its total assets. The Fund may also invest up to 10% of its total assets in preferred securities.
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 restrictions described in the Fund’s prospectus or Statement of Additional Information. The Fund may invest in derivatives, such as credit default swaps, on indexes of securities which may include exposure to issuers that the Fund is not permitted to invest in directly. 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).

2  Prospectus | PIMCO Funds

Prospectus

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. Additionally, a smaller fund may be more adversely affected by large purchases or redemptions of fund shares
Climate-Related Investing Risk:the risk that, because the Fund’s climate-related investment strategy may select or exclude securities of certain issuers for reasons in addition to performance, the Fund may differ from funds that do not utilize a climate-related investment strategy. Climate-related investing is qualitative and subjective by nature, and there is no guarantee that the factors utilized by PIMCO or any judgment exercised by PIMCO will reflect the opinions of any particular investor
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 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 credit, call and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer’s continuing ability to make principal and interest payments, and 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 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
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 investments 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. 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 OTC derivatives or other similar investments. The primary credit risk on derivatives 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
Equity Risk:the risk that the value of equity 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 securities generally have greater price volatility than fixed income securities
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 or other asset-backed securities, including junior and/or equity tranches (to the extent consistent with 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

July 31, 2023 (as supplemented September 29, 2023) | Prospectus  3

PIMCO Climate Bond Fund

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, or 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
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
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
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 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
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 a broad-based securities market index and an index of similar funds. 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. Performance for Class A and Class C 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.
The Fund’s benchmark index is the Bloomberg MSCI Global Green Bond Index, USD Hedged which offers investors an objective and robust measure of the global market for fixed income securities issued to fund projects with direct environmental benefits. An independent research driven methodology is used to evaluate index-eligible green bonds to ensure they adhere to established Green Bond Principles and to classify bonds by their environmental use of proceeds. It is not possible to invest directly in an unmanaged index. Lipper General Bond Funds Average is a total return performance average of Funds tracked by Lipper, Inc. that do not have any quality or maturity restrictions. These funds intend to keep the bulk of their assets in corporate and government debt issues.
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.

4  Prospectus | PIMCO Funds

Prospectus


Calendar Year Total Returns — Institutional Class
Best Quarter
June 30, 2020
8.11%
Worst Quarter
June 30, 2022
-5.85%
Year-to-Date
June 30, 2023
2.62%
Average Annual Total Returns (for periods ended 12/31/22)
 
1 Year
Since
Inception
Inception
Date
Institutional Class Return Before Taxes
-12.57%
-2.24%
12/10/2019
Institutional Class Return After Taxes on
Distributions(1)
-14.68%
-3.62%
 
Institutional Class Return After Taxes on
Distributions and Sales of Fund Shares(1)
-7.43%
-2.22%
 
I-2 Return Before Taxes
-12.66%
-2.34%
12/10/2019
I-3 Return Before Taxes
-12.70%
-2.39%
12/10/2019
Class A Return Before Taxes
-14.84%
-3.35%
12/10/2019
Class C Return Before Taxes
-14.40%
-3.37%
12/10/2019
Bloomberg MSCI Global Green Bond Index, USD
Hedged (reflects no deductions for fees, expenses
or taxes)
-17.01%
-4.74%
 
Lipper General Bond Funds Average (reflects no
deductions for taxes)(2)
-12.74%
-2.59%
 
1
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.
2
The Lipper Average’s since inception return is determined from the nearest month-end following the Fund’s inception date and not from the actual inception date of the Fund.
Investment Adviser/Portfolio Managers
PIMCO serves as the investment adviser for the Fund. The Fund’s portfolio is jointly and primarily managed by Jelle Brons, Regina Borromeo, Grover Burthey and Samuel Mary. Messrs. Brons and Ms. Borromeo and Burthey are Executive Vice Presidents of PIMCO. Mr. Mary is a Senior Vice President of PIMCO. Messrs. Brons and Mary have jointly and primarily managed the Fund since its inception in December 2019. Mr. Burthey has jointly and primarily managed the Fund since August 2022. Ms. Borromeo has jointly and primarily managed the Fund since June 2023.
Other Important Information Regarding Fund Shares
For important information about purchase and sale of Fund shares, tax information, and payments to broker-dealers and other financial intermediaries, please turn to the “Summary of Other Important Information Regarding Fund Shares” section on page 70 of this prospectus.

July 31, 2023 (as supplemented September 29, 2023) | Prospectus  5

PIMCO Dynamic Bond Fund

Investment Objective
The Fund seeks maximum long-term 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. 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 91 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
Class A
Class C
Class R
Maximum Sales
Charge (Load)
Imposed on
Purchases (as a
percentage of
offering price)
None
None
None
3.75%
None
None
Maximum Deferred
Sales Charge (Load)
(as a percentage of
the lower of the
original purchase
price or redemption
price)
None
None
None
1.00%
1.00%
None
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
Class A
Class C
Class R
Management Fees
0.80%
0.90%
1.00%
0.95%
0.95%
0.95%
Distribution and/or
Service (12b-1) Fees
N/A
N/A
N/A
0.25%
1.00%
0.50%
Other Expenses(1)
0.04%
0.04%
0.03%
0.04%
0.04%
0.04%
Total Annual
Fund Operating
Expenses
0.84%
0.94%
1.03%
1.24%
1.99%
1.49%
Fee Waiver and/or
Expense
Reimbursement(2)(3)
(0.05%)
(0.05%)
(0.10%)
(0.05%)
(0.05%)
(0.05%)
Total Annual
Fund Operating
Expenses After
Fee Waiver
and/or Expense
Reimbursement(4)
0.79%
0.89%
0.93%
1.19%
1.94%
1.44%
1
“Other Expenses” include interest expense of 0.03%. 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 After Fee Waiver and/or Expense Reimbursement are 0.76%, 0.86%, 0.90%,1.16%, 1.91% and 1.41% for Institutional Class, I-2, I-3, Class A, Class C and Class R shares, respectively.
2
PIMCO has contractually agreed, through July 31, 2024, 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.
3
PIMCO has contractually agreed, through August 31, 2024, to waive its advisory fee by 0.05% of the average daily net assets attributable to the Fund. This Fee Waiver Agreement may be terminated by PIMCO Funds (the “Trust”) upon 90 days' prior written notice to PIMCO.
4
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement have been restated to reflect current expenses and fee waivers.
Example.The Example is intended to help you compare the cost of investing in Institutional Class, I-2, I-3, Class A, Class C or Class R 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
$81
$263
$461
$1,033
I-2
$91
$295
$515
$1,150
I-3
$95
$318
$559
$1,250
Class A
$492
$749
$1,026
$1,814
Class C
$297
$620
$1,068
$2,313
Class R
$147
$466
$808
$1,775
If you do not redeem your shares:
 
1 Year
3 Years
5 Years
10 Years
Class A
$492
$749
$1,026
$1,814
Class C
$197
$620
$1,068
$2,313
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 174% 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 Fixed Income Instruments of varying maturities, 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. The Fund intends to

6  PIMCO Funds | Prospectus

Prospectus

utilize various investment strategies in a broad array of fixed income sectors to achieve its investment objective. The Fund will not be constrained by management against an index. The average portfolio duration of this Fund will normally vary from (negative) 3 years to positive 8 years based on PIMCO’s market forecasts. 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.
The Fund may invest in both investment-grade securities and high yield securities (“junk bonds”) subject to a maximum of 40% of its total assets in securities rated below Baa by Moody’s Investors Service, Inc. (“Moody’s”), or equivalently rated by Standard & Poor’s Ratings Services (“S&P”) or Fitch, Inc. (“Fitch”), or, if unrated, determined by PIMCO to be of comparable quality. In the even 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 also invest without limitation in securities denominated in foreign currencies and in U.S. dollar-denominated securities of foreign issuers. In addition, the Fund may invest up to 50% of its total assets in securities and instruments that are economically tied to emerging market countries (this limitation does not apply to investment grade sovereign debt denominated in the local currency with less than 1 year remaining to maturity, which means the Fund may invest in such instruments without limitation subject to any applicable legal or regulatory limitation). The Fund will normally limit its foreign currency exposure (from non-U.S. dollar-denominated securities or currencies) to 35% of its total assets. The Fund may also invest up to 10% of its total assets in preferred securities.
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 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, 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).
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.
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 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 credit, call and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer’s continuing ability to make principal and interest payments, and 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 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
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 investments 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. 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,

July 31, 2023 (as supplemented September 29, 2023) | Prospectus  7

PIMCO Dynamic Bond Fund

as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives or other similar investments. The primary credit risk on derivatives 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
Equity Risk:the risk that the value of equity 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 securities generally have greater price volatility than fixed income securities
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 or other asset-backed securities, including junior and/or equity tranches (to the extent consistent with other of the Fund’s guidelines), which generally carry higher levels of the foregoing risks
Collateralized Loan Obligations Risk: the risk that investing in collateralized loan obligations (“CLOs”) and other similarly structured investments exposes the Fund to heightened credit risk, interest rate risk, liquidity risk, market risk and prepayment and extension risk, as well as the risk of default on the underlying asset. In addition, investments in CLOs carry additional risks including, but not limited to, the risk that: (i) distributions from the collateral may not be adequate to make interest or other payments; (ii) the quality of the collateral may decline in value or default; (iii) the Fund may invest in tranches of CLOs that are subordinate to other tranches; (iv) the structure and complexity of the transaction and the legal documents could lead to disputes among investors regarding the characterization of proceeds; and (v) the CLO’s manager may perform poorly
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, or 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
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
Management Risk:the risk that the investment techniques and risk analyses applied by PIMCO 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
LIBOR Transition Risk:the risk related to the anticipated 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

8  Prospectus | PIMCO Funds

Prospectus

showing how the Fund’s average annual returns compare with the returns of a broad-based securities market index and an index of similar funds. 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. For periods prior to the inception date of I-3 shares (April 27, 2018), performance information shown in the table for that class is based on the performance of the Fund’s Institutional Class shares, adjusted to reflect the fees and expenses paid by that class of shares. Performance for Class A and Class C 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.
The Fund’s broad-based securities market index is the ICE BofA SOFR Overnight Rate Index. The ICE BofA SOFR Overnight Rate Index tracks the performance of a synthetic asset paying SOFR to a stated maturity. The index is based on the assumed purchase at par of a synthetic instrument having exactly its stated maturity and with a coupon equal to that day’s fixing rate. That issue is assumed to be sold the following business day (priced at a yield equal to the current day fixing rate) and rolled into a new instrument. SOFR (Secured Overnight Funding Rate) is an overnight rate (published in arrears) and was chosen by the Alternative Reference Rates Committee (“ARRC”) as the successor to the USD LIBOR (London Interbank Offered Rate). SOFR is secured (collateralized by Treasuries), calculated by the Federal Reserve Bank of New York, and transactions based. Prior to July 1, 2022, the Fund’s broad-based securities market index was the 3 Month USD LIBOR Index. The Fund’s new benchmark index was selected to replace the 3 Month USD LIBOR Index in light of the upcoming cessation of 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 (3 months) in England’s Eurodollar market. The Lipper Absolute Return Bond Funds Average is a total return performance average of Funds tracked by Lipper, Inc. that aim for positive returns in all market conditions and invest primarily in debt securities. The funds are not benchmarked against a traditional long-only market index but rather have the aim of outperforming a cash or risk-free benchmark.
 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
6.42%
Worst Quarter
March 31, 2020
-5.22%
Year-to-Date
June 30, 2023
2.34%
Average Annual Total Returns (for periods ended 12/31/22)
 
1 Year
5 Years
10 Years
Institutional Class Return Before Taxes
-6.89%
1.03%
1.53%
Institutional Class Return After Taxes on Distributions(1)
-8.47%
-0.46%
0.09%
Institutional Class Return After Taxes on Distributions
and Sales of Fund Shares(1)
-4.07%
0.18%
0.54%
I-2 Return Before Taxes
-6.98%
0.93%
1.43%
I-3 Return Before Taxes
-7.03%
0.88%
1.43%
Class A Return Before Taxes
-10.70%
-0.14%
0.74%
Class C Return Before Taxes
-8.85%
-0.13%
0.38%
Class R Return Before Taxes
-7.49%
0.37%
0.88%
ICE BofA SOFR Overnight Rate Index (reflects no
deductions for fees, expenses or taxes)(2)
1.66%
-
-
3 Month USD LIBOR Index (reflects no deductions for
fees, expenses or taxes)
1.80%
1.53%
1.03%
Lipper Absolute Return Bond Funds Average (reflects
no deductions for taxes)
-6.46%
0.89%
1.61%
1
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.
2
ICE BofA SOFR Overnight Rate Index was first published on October 1, 2019.

July 31, 2023 (as supplemented September 29, 2023) | Prospectus  9

PIMCO Dynamic Bond Fund

Investment Adviser/Portfolio Managers
PIMCO serves as the investment adviser for the Fund. The Fund’s portfolio is jointly and primarily managed by Marc Seidner, Daniel J. Ivascyn and Mohit Mittal. Mr. Seidner is CIO Non-traditional Strategies, and Mr. Ivascyn is Group Chief Investment Officer. Each of Messrs. Seidner, Ivascyn and Mittal is a Managing Director of PIMCO. Mr. Seidner has managed the Fund since January 2015, Mr. Ivascyn has managed the Fund since September 2014 and Mr. Mittal has managed the Fund since January 2022.
Other Important Information Regarding Fund Shares
For important information about purchase and sale of Fund shares, tax information, and payments to broker-dealers and other financial intermediaries, please turn to the “Summary of Other Important Information Regarding Fund Shares” section on page 70 of this prospectus.

10  Prospectus | PIMCO Funds

PIMCO Extended Duration Fund

Investment Objective
The Fund seeks maximum total return, consistent with 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. 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 91 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
Class A
Maximum Sales Charge (Load) Imposed on Purchases (as a
percentage of offering price)
None
None
3.75%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower
of the original purchase price or redemption price)
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
Class A
Management Fees
0.50%
0.60%
0.65%
Distribution and/or Service (12b-1) Fees
N/A
N/A
0.25%
Other Expenses(1)
2.52%
2.52%
2.52%
Total Annual Fund Operating Expenses
3.02%
3.12%
3.42%
1
“Other Expenses” include interest expense of 2.52%. 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 0.50%, 0.60% and 0.90% for Institutional Class, I-2 and Class A shares, respectively. Interest expense is calculated and presented equally across all share classes. As a result, Total Annual Fund Operating Expenses 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.
Example.The Example is intended to help you compare the cost of investing in Institutional Class, I-2 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
$305
$933
$1,587
$3,337
I-2
$315
$963
$1,635
$3,430
Class A
$707
$1,386
$2,087
$3,939
If you do not redeem your shares:
 
1 Year
3 Years
5 Years
10 Years
Class A
$707
$1,386
$2,087
$3,939
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 119% 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 65% of its total assets in a diversified portfolio of Fixed Income Instruments of varying maturities, 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. The average portfolio duration of this Fund normally varies within three years (plus or minus) of the portfolio duration of the securities comprising the FTSE STRIPS Index, 20+ Year Sub-Index, as calculated by PIMCO, which as of May 31, 2023 was 25.21 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.
The Fund invests primarily in investment grade debt securities, but may invest up to 10% of its total assets in high yield securities (“junk bonds”) that are rated B or higher by Moody’s Investors Service, Inc. (“Moody’s”), or equivalently rated by Standard & Poor’s Ratings Services (“S&P”) or Fitch, 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 up to 30% of its total assets in securities denominated in foreign currencies, and may invest beyond this limit in U.S. dollar-denominated securities of foreign issuers. The Fund may invest up to 15% of its total assets in securities and instruments that are economically tied to emerging market countries (this limitation does not apply to investment grade sovereign debt denominated in the local currency with less than 1 year remaining to maturity, which means the Fund may invest, together with any other investments denominated in foreign currencies, up to 30% of its total

PIMCO Funds | Prospectus  11

PIMCO Extended Duration Fund

assets in such instruments). The Fund will normally limit its foreign currency exposure (from non-U.S. dollar-denominated securities or currencies) to 20% of its total assets.
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 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, 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. The Fund may also invest up to 10% of its total assets in preferred securities.
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.
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 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 credit, call and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer’s continuing ability to make principal and interest payments, and 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 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
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 investments 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. 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 OTC derivatives or other similar investments. The primary credit risk on derivatives 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
Equity Risk:the risk that the value of equity 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 securities generally have greater price volatility than fixed income securities
Mortgage-Related and Other Asset-Backed Securities Risk:the risks of investing in mortgage-related and other asset-backed securities,

12  Prospectus | PIMCO Funds

Prospectus

including interest rate risk, extension risk, prepayment risk and credit risk. The Fund may invest in any tranche of mortgage-related or other asset-backed securities, including junior and/or equity tranches (to the extent consistent with 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, or 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
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
Management Risk:the risk that the investment techniques and risk analyses applied by PIMCO 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
LIBOR Transition Risk:the risk related to the anticipated 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 a broad-based securities market index and an index of similar funds. 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 Class A shares of the Fund have not commenced operations as of the date of this prospectus. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.
The FTSE STRIPS Index, 20+ Year Sub-Index represents a composition of outstanding Treasury Bonds and Notes with a maturity of at least twenty years. The index is rebalanced each month in accordance with underlying Treasury figures and profiles provided as of the previous month-end. The included STRIPS are derived only from bonds in the FTSE Bond Index, which include coupon strips with less than one year remaining to maturity. The Lipper Corporate Debt Funds BBB-Rated Funds Average consists of funds that invest at least 65% of their assets in corporate and government debt issues rated in the top four grades.
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.

July 31, 2023 (as supplemented September 29, 2023) | Prospectus  13

PIMCO Extended Duration Fund


Calendar Year Total Returns — Institutional Class
Best Quarter
March 31, 2020
30.12%
Worst Quarter
March 31, 2021
-17.87%
Year-to-Date
June 30, 2023
6.22%
Average Annual Total Returns (for periods ended 12/31/22)
 
1 Year
5 Years
10 Years
Institutional Class Return Before Taxes
-39.84%
-4.09%
0.31%
Institutional Class Return After Taxes on Distributions(1)
-40.63%
-6.87%
-2.20%
Institutional Class Return After Taxes on Distributions
and Sales of Fund Shares(1)
-23.49%
-2.55%
0.07%
I-2 Return Before Taxes
-39.90%
-4.19%
0.21%
FTSE STRIPS Index, 20+ Year Sub-Index (reflects no
deductions for fees, expenses or taxes)
-40.21%
-4.05%
0.44%
Lipper Corporate Debt Funds BBB-Rated Funds
Average (reflects no deductions for taxes)
-15.92%
0.18%
1.66%
1
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 Mike Cudzil and Steve Rodosky. Messrs. Cudzil and Rodosky are Managing Directors of PIMCO. Mr. Cudzil has managed the Fund since February 2016. Mr. Rodosky has managed the Fund since July 2007.
Other Important Information Regarding Fund Shares
For important information about purchase and sale of Fund shares, tax information, and payments to broker-dealers and other financial intermediaries, please turn to the “Summary of Other Important Information Regarding Fund Shares” section on page 70 of this prospectus.

14  Prospectus | PIMCO Funds

PIMCO GNMA and Government Securities Fund

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. 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 91 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
Class A
Class C
Maximum Sales Charge (Load) Imposed on
Purchases (as a percentage of offering price)
None
None
None
3.75%
None
Maximum Deferred Sales Charge (Load) (as a
percentage of the lower of the original purchase
price or redemption price)
None
None
None
1.00%
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
Class A
Class C
Management Fees
0.50%
0.60%
0.70%
0.65%
0.65%
Distribution and/or Service (12b-1) Fees
N/A
N/A
N/A
0.25%
1.00%
Other Expenses(1)
0.84%
0.84%
0.84%
0.84%
0.84%
Total Annual Fund Operating Expenses
1.34%
1.44%
1.54%
1.74%
2.49%
Fee Waiver and/or Expense Reimbursement(2)
N/A
N/A
(0.05%)
N/A
N/A
Total Annual Fund Operating Expenses
After Fee Waiver and/or Expense
Reimbursement
1.34%
1.44%
1.49%
1.74%
2.49%
1
“Other Expenses” include interest expense of 0.84%. 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 After Fee Waiver and/or Expense Reimbursement are 0.50%, 0.60%, 0.65%, 0.90% and 1.65% for Institutional Class, I-2, I-3, Class A and Class C 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.
2
PIMCO has contractually agreed, through July 31, 2024, 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.
Example.The Example is intended to help you compare the cost of investing in Institutional Class, I-2, I-3, Class A or Class C 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
$136
$425
$734
$1,613
I-2
$147
$456
$787
$1,724
I-3
$152
$482
$835
$1,830
Class A
$545
$902
$1,283
$2,350
Class C
$352
$776
$1,326
$2,826
If you do not redeem your shares:
 
1 Year
3 Years
5 Years
10 Years
Class A
$545
$902
$1,283
$2,350
Class C
$252
$776
$1,326
$2,826
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 1167% 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 securities of varying maturities issued by the Government National Mortgage Association (“GNMA”) and of securities issued or guaranteed by the U.S. Government, its agencies or government-sponsored enterprises, which may be represented by forwards or derivatives such as options, futures contracts or swap agreements. The Fund is neither sponsored by nor affiliated with GNMA. The average portfolio duration of this Fund normally varies from one to seven years based on PIMCO’s market forecasts. 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. The Fund may invest without limit in securities issued or guaranteed by the U.S. Government, its agencies or government-sponsored enterprises. In addition, the Fund may invest up to 10% of its total assets in investment grade securities rated below Aaa by Moody’s Investors Service, Inc. (“Moody’s”), or equivalently rated by Standard & Poor’s Ratings Services (“S&P”) or Fitch, Inc. (“Fitch”), subject to a minimum rating of Baa by Moody’s, or equivalently rated by S&P or Fitch, or, if unrated, determined by PIMCO

PIMCO Funds | Prospectus  15

PIMCO GNMA and Government Securities Fund

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 not invest in securities denominated in foreign currencies, but may invest without limit in U.S. dollar-denominated securities of foreign issuers. The Fund may invest up to 10% of its total assets in U.S. dollar-denominated securities and instruments that are economically tied to emerging market countries.
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 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, 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 or improving credit fundamentals for a particular sector or security.
GNMA, a wholly owned U.S. Government corporation, is authorized to guarantee, with the full faith and credit of the U.S. Government, the timely payment of principal and interest on securities issued by institutions approved by GNMA and backed by pools of mortgages insured by the Federal Housing Administration, or guaranteed by the Department of Veterans Affairs. The Fund may also invest up to 10% of its total assets in preferred securities.
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.
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
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
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 investments 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. 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 OTC derivatives or other similar investments. The primary credit risk on derivatives 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
Equity Risk:the risk that the value of equity securities, such as common stocks and preferred securities, may decline due to general market conditions which are not specifically related to a particular

16  Prospectus | PIMCO Funds

Prospectus

company or to factors affecting a particular industry or industries. Equity securities generally have greater price volatility than fixed income securities
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 or other asset-backed securities, including junior and/or equity tranches (to the extent consistent with 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, or 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
Emerging Markets Risk:the risk of investing in emerging market securities, primarily increased foreign (non-U.S.) investment risk
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 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
LIBOR Transition Risk:the risk related to the anticipated 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 a broad-based securities market index and an index of similar funds. 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. Performance for Class A and Class C 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.
The Bloomberg GNMA Index is an unmanaged index covering mortgage-backed pass-through securities of the GNMA. The Lipper GNMA Funds Average is a total return performance average of funds tracked by Lipper, Inc. that invest at least 65% of their assets in mortgages/securities issued or guaranteed as to principal and interest by the U.S. government and certain federal agencies.
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
March 31, 2020
2.65%
Worst Quarter
September 30, 2022
-5.74%
Year-to-Date
June 30, 2023
2.89%

July 31, 2023 (as supplemented September 29, 2023) | Prospectus  17

PIMCO GNMA and Government Securities Fund

Average Annual Total Returns (for periods ended 12/31/22)
 
1 Year
5 Years
10 Years
Institutional Class Return Before Taxes
-12.96%
-0.35%
0.69%
Institutional Class Return After Taxes on Distributions(1)
-14.64%
-1.62%
-0.55%
Institutional Class Return After Taxes on Distributions
and Sales of Fund Shares(1)
-7.63%
-0.75%
0.01%
I-2 Return Before Taxes
-13.04%
-0.45%
0.59%
I-3 Return Before Taxes
-13.08%
-0.50%
0.54%
Class A Return Before Taxes
-16.52%
-1.51%
-0.09%
Class C Return Before Taxes
-14.78%
-1.49%
-0.46%
Bloomberg GNMA Index (reflects no deductions for
fees, expenses or taxes)
-10.76%
-0.50%
0.59%
Lipper GNMA Funds Average (reflects no deductions
for taxes)
-10.79%
-0.76%
0.10%
1
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 Mike Cudzil, Daniel Hyman and Munish Gupta. Messrs. Cudzil and Hyman are Managing Directors of PIMCO. Mr. Cudzil has managed the Fund since January 2013, and Mr. Hyman has managed the Fund since July 2012. Mr. Gupta is an Executive Vice President of PIMCO and has managed the Fund since August 2022.
Other Important Information Regarding Fund Shares
For important information about purchase and sale of Fund shares, tax information, and payments to broker-dealers and other financial intermediaries, please turn to the “Summary of Other Important Information Regarding Fund Shares” section on page 70 of this prospectus.

18  Prospectus | PIMCO Funds

PIMCO Investment Grade Credit Bond Fund

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. 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 91 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
Class C
Maximum Sales
Charge (Load)
Imposed on
Purchases (as a
percentage of
offering price)
None
None
None
None
3.75%
None
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%
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
Class C
Management Fees
0.50%
0.60%
0.70%
0.50%
0.65%
0.65%
Distribution and/or
Service (12b-1) Fees
N/A
N/A
N/A
0.25%
0.25%
1.00%
Other Expenses(1)
0.54%
0.54%
0.54%
0.54%
0.54%
0.54%
Total Annual
Fund Operating
Expenses
1.04%
1.14%
1.24%
1.29%
1.44%
2.19%
Fee Waiver and/or
Expense
Reimbursement(2)
N/A
N/A
(0.05%)
N/A
N/A
N/A
Total Annual
Fund Operating
Expenses After
Fee Waiver
and/or Expense
Reimbursement
1.04%
1.14%
1.19%
1.29%
1.44%
2.19%
1
“Other Expenses” include interest expense of 0.54%. 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 After Fee Waiver and/or Expense Reimbursement are 0.50%, 0.60%, 0.65%, 0.75%, 0.90% and 1.65% for Institutional Class, I-2, I-3, Administrative Class, Class A and Class C shares, respectively.
2
PIMCO has contractually agreed, through July 31, 2024, 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.
Example.The Example is intended to help you compare the cost of investing in Institutional Class, I-2, I-3, Administrative Class, Class A or Class C 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
$106
$331
$574
$1,271
I-2
$116
$362
$628
$1,386
I-3
$121
$388
$676
$1,496
Administrative Class
$131
$409
$708
$1,556
Class A
$516
$813
$1,132
$2,034
Class C
$322
$685
$1,175
$2,524
If you do not redeem your shares:
 
1 Year
3 Years
5 Years
10 Years
Class A
$516
$813
$1,132
$2,034
Class C
$222
$685
$1,175
$2,524
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 78% 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 investment grade fixed income securities of varying maturities, which may be represented by forwards or derivatives such as options, futures contracts or swap agreements. Assets not invested in investment grade fixed income securities may be invested in other types of Fixed Income 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 average portfolio duration of this Fund normally varies within two years (plus or minus) of the portfolio duration of the securities comprising the Bloomberg U.S. Credit Index, as calculated by PIMCO, which as of May 31, 2023 was 6.74 years.

PIMCO Funds | Prospectus  19

PIMCO Investment Grade Credit Bond Fund

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.
The Fund invests primarily in investment grade debt securities, but may invest up to 15% of its total assets in high yield securities (“junk bonds”), as rated by Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor’s Ratings Services (“S&P”) or Fitch, Inc. (“Fitch”), or, if unrated, as determined by PIMCO. Investment grade debt securities are rated Baa or higher by Moody’s, or equivalently rated by S&P or 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 up to 30% of its total assets in securities denominated in foreign currencies, and may invest beyond this limit in U.S. dollar-denominated securities of foreign issuers. The Fund may invest up to 25% of its total assets in securities and instruments that are economically tied to emerging market countries (this limitation does not apply to investment grade sovereign debt denominated in the local currency with less than 1 year remaining to maturity, which means the Fund may invest, together with any other investments denominated in foreign currencies, up to 30% of its total assets in such instruments). The Fund will normally limit its foreign currency exposure (from non-U.S. dollar-denominated securities or currencies) to 20% of its total assets.
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 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, 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. The Fund may also invest up to 10% of its total assets in preferred securities.
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.
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 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 credit, call and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer’s continuing ability to make principal and interest payments, and 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 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
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 investments 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. Over-the-counter (“OTC”) derivatives or other

20  Prospectus | PIMCO Funds

Prospectus

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 OTC derivatives or other similar investments. The primary credit risk on derivatives 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
Equity Risk:the risk that the value of equity 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 securities generally have greater price volatility than fixed income securities
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 or other asset-backed securities, including junior and/or equity tranches (to the extent consistent with 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, or 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
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
Management Risk:the risk that the investment techniques and risk analyses applied by PIMCO 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
LIBOR Transition Risk:the risk related to the anticipated 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 a broad-based securities market index and an index of similar funds. 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. For periods prior to the inception date of I-3 shares (April 27, 2018), performance information shown in the table for that class is based on the performance of the Fund’s Institutional Class shares, adjusted to reflect the fees and expenses paid by that class of shares. Performance for Class A and Class C shares in

July 31, 2023 (as supplemented September 29, 2023) | Prospectus  21

PIMCO Investment Grade Credit Bond Fund

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.
The Bloomberg U.S. Credit Index is an unmanaged index comprised of publicly issued U.S. corporate and specified non-U.S. debentures and secured notes that meet the specified maturity, liquidity, and quality requirements. To qualify, bonds must be SEC-registered. The Lipper Corporate Debt Funds BBB-Rated Funds Average is a total return performance average of funds tracked by Lipper, Inc. that invest at least 65% of their assets in investment-grade debt issues (rated in the top four grades) with dollar-weighted average maturities of five to ten years.
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
8.59%
Worst Quarter
March 31, 2022
-7.96%
Year-to-Date
June 30, 2023
3.54%
Average Annual Total Returns (for periods ended 12/31/22)
 
1 Year
5 Years
10 Years
Institutional Class Return Before Taxes
-15.83%
0.13%
2.23%
Institutional Class Return After Taxes on Distributions(1)
-17.25%
-1.49%
0.31%
Institutional Class Return After Taxes on Distributions
and Sales of Fund Shares(1)
-9.35%
-0.49%
0.93%
I-2 Return Before Taxes
-15.92%
0.03%
2.13%
I-3 Return Before Taxes
-15.96%
-0.01%
2.08%
Administrative Return Before Taxes
-16.04%
-0.12%
1.97%
Class A Return Before Taxes
-19.34%
-1.03%
1.44%
Class C Return Before Taxes
-17.61%
-1.01%
1.06%
Bloomberg U.S. Credit Index (reflects no deductions for
fees, expenses or taxes)
-15.26%
0.42%
1.82%
Lipper Corporate Debt Funds BBB-Rated Funds
Average (reflects no deductions for taxes)
-15.92%
0.18%
1.66%
1
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 Mark Kiesel, Mohit Mittal and Amit Arora. Mr. Kiesel is CIO Global Credit and a Managing Director of PIMCO. Mr. Mittal is a Managing Director of PIMCO. Mr. Arora is an Executive Vice President of PIMCO. Mr. Kiesel has managed the Fund since November 2002, and Messrs. Mittal and Arora have managed the Fund since October 2016.
Other Important Information Regarding Fund Shares
For important information about purchase and sale of Fund shares, tax information, and payments to broker-dealers and other financial intermediaries, please turn to the “Summary of Other Important Information Regarding Fund Shares” section on page 70 of this prospectus.

22  Prospectus | PIMCO Funds

PIMCO Long Duration Total Return Fund

Investment Objective
The Fund seeks maximum total return, consistent with 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. 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 91 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
Class A
Class C
Maximum Sales Charge (Load) Imposed on Purchases (as a
percentage of offering price)
None
None
3.75%
None
Maximum Deferred Sales Charge (Load) (as a percentage of
the lower of the original purchase price or redemption price)
None
None
1.00%
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
Class A
Class C
Management Fees
0.50%
0.60%
0.65%
0.65%
Distribution and/or Service (12b-1) Fees
N/A
N/A
0.25%
1.00%
Other Expenses(1)
1.23%
1.23%
1.23%
1.23%
Total Annual Fund Operating Expenses
1.73%
1.83%
2.13%
2.88%
1
“Other Expenses” include interest expense of 1.23%. 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 0.50%, 0.60%, 0.90% and 1.65% for Institutional Class, I-2, Class A and Class C shares, respectively. Interest expense is calculated and presented equally across all share classes. As a result, Total Annual Fund Operating Expenses 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.
Example.The Example is intended to help you compare the cost of investing in Institutional Class, I-2, Class A or Class C 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
$176
$545
$939
$2,041
I-2
$186
$576
$990
$2,148
Class A
$583
$1,017
$1,476
$2,745
Class C
$391
$892
$1,518
$3,205
If you do not redeem your shares:
 
1 Year
3 Years
5 Years
10 Years
Class A
$583
$1,017
$1,476
$2,745
Class C
$291
$892
$1,518
$3,205
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 161% 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 65% of its total assets in a diversified portfolio of Fixed Income Instruments of varying maturities, 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. The average portfolio duration of this Fund normally varies within two years (plus or minus) of the portfolio duration of the securities comprising the Bloomberg Long-Term Government/ Credit Index, as calculated by PIMCO, which as of May 31, 2023 was 14.02 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.
The Fund invests primarily in investment grade debt securities, but may invest up to 10% of its total assets in high yield securities (“junk bonds”), as rated by Moody’s Investors Service, Inc. (“Moody’s”), Standard & Poor’s Ratings Services (“S&P”) or Fitch, Inc. (“Fitch”), or, if unrated, as determined by PIMCO. 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 up to 30% of its total assets in securities denominated in foreign currencies, and may invest beyond this limit in U.S. dollar-denominated securities of foreign issuers. The Fund may invest up to 15% of its total assets in securities and instruments that are economically tied to emerging market countries (this limitation does not apply to investment grade sovereign debt denominated in the local currency with less than 1 year remaining to maturity, which means the Fund may invest, together with

PIMCO Funds | Prospectus  23

PIMCO Long Duration Total Return Fund

any other investments denominated in foreign currencies, up to 30% of its total assets in such instruments). The Fund will normally limit its foreign currency exposure (from non-U.S. dollar-denominated securities or currencies) to 20% of its total assets.
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 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, 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. The Fund may also invest up to 10% of its total assets in preferred securities.
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.
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 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 credit, call and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer’s continuing ability to make principal and interest payments, and 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 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
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 investments 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. 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 OTC derivatives or other similar investments. The primary credit risk on derivatives 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
Equity Risk:the risk that the value of equity 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 securities generally have greater price volatility than fixed income securities
Mortgage-Related and Other Asset-Backed Securities Risk:the risks of investing in mortgage-related and other asset-backed securities,

24  Prospectus | PIMCO Funds

Prospectus

including interest rate risk, extension risk, prepayment risk and credit risk. The Fund may invest in any tranche of mortgage-related or other asset-backed securities, including junior and/or equity tranches (to the extent consistent with 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, or 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
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
Management Risk:the risk that the investment techniques and risk analyses applied by PIMCO 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
LIBOR Transition Risk:the risk related to the anticipated 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 a broad-based securities market index and an index of similar funds. 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. For periods prior to the inception date of Class A shares (September 8, 2017) and Class C shares (January 5, 2018) performance information shown in the table for these classes is based on the performance of the Fund’s Institutional Class shares, adjusted to reflect the fees and expenses paid by these classes of shares. 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.
The Bloomberg Long-Term Government/Credit Index is an unmanaged index of U.S. Government or Investment Grade Credit Securities having a maturity of 10 years or more. The Lipper Corporate Debt Funds BBB-Rated Funds Average consists of funds that invest at least 65% of their assets in corporate and government debt issues rated in the top four grades.
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.

July 31, 2023 (as supplemented September 29, 2023) | Prospectus  25

PIMCO Long Duration Total Return Fund


Calendar Year Total Returns — Institutional Class
Best Quarter
June 30, 2020
7.62%
Worst Quarter
June 30, 2022
-13.17%
Year-to-Date
June 30, 2023
5.04%
Average Annual Total Returns (for periods ended 12/31/22)
 
1 Year
5 Years
10 Years
Institutional Class Return Before Taxes
-27.58%
-0.87%
1.97%
Institutional Class Return After Taxes on Distributions(1)
-28.73%
-3.71%
-0.73%
Institutional Class Return After Taxes on Distributions
and Sales of Fund Shares(1)