Summary Prospectus by Investment Company (Form 497K)

OPPORTUNISTIC MUNICIPAL FUND

Class			A			Inst.
Ticker Symbol(s)			PMOAX			POMFX

Principal Funds, Inc. Summary Prospectus December 31, 2025

Before you invest, you may want to review the Fund's Prospectus, which contains more information about the Fund and its risks. You can find the Fund's Prospectus, Statement of Additional Information, Reports to Shareholders, and other information about the Fund online at www.PrincipalAM.com/Prospectuses. You can also get this information at no cost by calling 1-800-222-5852 or by sending an email request to [email protected].

The Fund's Prospectus and Statement of Additional Information, both dated December 31, 2025, as may be amended or supplemented, are incorporated by reference into this Summary Prospectus.

Objective

The Fund seeks to provide a high level of income that is exempt from federal income tax while protecting investors' capital.

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 tables and examples 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 Principal Funds, Inc. More information about these and other discounts is available from your financial intermediary and in "Choosing a Share Class and The Costs of Investing" beginning on page 105 of the Fund's Prospectus, Appendix B to the Prospectus titled "Intermediary-Specific Sales Charge Waivers and Reductions," and "Multiple Class Structure" beginning on page 60 of the Fund's Statement of Additional Information.

If you purchase Institutional Class shares through certain programs offered by certain financial intermediaries, you may be required to pay a commission and/or other forms of compensation to the broker, or to your Financial Professional or other financial intermediary.

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Shareholder Fees (fees paid directly from your investment)

			Share Class
			A			Inst.
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)			3.75%			None
Maximum Deferred Sales Charge (Load) (as a percentage of the offering price or NAV when Sales Load is paid, whichever is less)			1.00%			None

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)

			Share Class
			A			Inst.
Management Fees			0.44%			0.44%
Distribution and/or Service (12b-1) Fees			0.25%			N/A
Other Expenses:
Interest Expenses			0.23%			0.23%
Remainder of Other Expenses (1)			0.15%			0.18%
Total Other Expenses			0.38%			0.41%
Total Annual Fund Operating Expenses			1.07%			0.85%
Expense Reimbursement (2)			0.00%			(0.05)%
Total Annual Fund Operating Expenses after Expense Reimbursement			1.07%			0.80%

(1) Includes 0.01% of interest expense associated with borrowings. The expense is not subject to the contractual expense limit.

(2) Principal Global Investors, LLC ("PGI"), the investment advisor, has contractually agreed to limit the Fund's expenses by paying, if necessary, expenses normally payable by the Fund (excluding interest expense, expenses related to fund investments, acquired fund fees and expenses, expenses related to the ReFlow liquidity program, and tax reclaim recovery expenses and other extraordinary expenses) to maintain a total level of operating expenses (expressed as a percent of average net assets on an annualized basis) not to exceed 0.84% for Class A and 0.56% for Institutional Class shares. It is expected that the expense limits will continue through the period ending December 30, 2026; however, Principal Funds, Inc. and PGI, the parties to the agreement, may mutually agree to terminate the expense limits prior to the end of the period. Subject to applicable expense limits, the Fund may reimburse PGI for expenses incurred during the current fiscal year.

Example

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of 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. The calculation of costs takes into account any applicable contractual fee waivers and/or expense reimbursements for the period noted in the table above. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

			1 year			3 years			5 years			10 years
Class A			$480			$703			$943			$1,632
Institutional Class			82			266			466			1,044

Portfolio Turnover

The Fund pays transaction costs, such as commissions, 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 Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 85.7% of the average value of its portfolio.

Principal Investment Strategies

Under normal circumstances, the Fund invests at least 80% of its net assets, plus any borrowings for investment purposes, in municipal obligations, which are securities issued by or on behalf of state or local governments and other public authorities. Municipal obligations generally pay interest that is exempt from federal income tax. The Fund's investment in municipal obligations include industrial revenue bonds. The Fund has a flexible investment strategy and invests in obligations of any duration and credit quality, including below-investment-grade bonds (sometimes called "high yield bonds" or "junk bonds"), which are rated at the time of purchase Ba1 or lower by Moody's Investors Service, Inc. ("Moody's") and BB+ or lower by S&P Global Ratings ("S&P Global"). If the bond has been rated by only one of the rating agencies, that rating will determine the bond's rating; if the bond is rated differently by the rating agencies, the highest rating will be used; and if the bond has not been rated by either of the rating agencies, those selecting such investments will determine the bond's quality. The Fund is not managed to a particular maturity or duration.

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The Fund also invests in inverse floating rate instruments, which are generally more volatile than other types of municipal obligations and may involve leverage, to enhance investment income.

Principal Risks

The value of your investment in the Fund changes with the value of the Fund's investments. Many factors affect that value, and it is possible to lose money by 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. The principal risks of investing in the Fund are listed below in alphabetical order and not in order of significance.

Fixed-Income Securities Risk. Fixed-income securities are subject to interest rate, credit quality, and liquidity risks. The market value of fixed-income securities generally declines when interest rates rise, and increased interest rates may adversely affect the liquidity of certain fixed-income securities. Moreover, an issuer of fixed-income securities could default on its payment obligations due to increased interest rates or for other reasons.

High Yield Securities Risk. High yield fixed-income securities (commonly referred to as "junk bonds") are subject to greater credit quality risk than higher rated fixed-income securities and should be considered speculative.

Industrial Revenue Bond Risk. The Fund will be sensitive to, and its performance will depend to a greater extent on, the overall condition and performance of industrial revenue bonds. These revenue bonds are issued by or on behalf of public authorities to obtain funds to finance various public and/or privately operated facilities, including those for business and manufacturing, housing, sports, pollution control, airport, mass transit, port, and parking facilities. These bonds are normally secured only by the revenues from the project and not by state or local government tax payments. Consequently, the credit quality of these bonds is dependent upon the ability of the user of the facilities financed by the bonds and any guarantor to meet its financial obligations.

Inverse Floating Rate Investments Risk. Inverse floating rate investments are extremely sensitive to changes in interest rates and, in some cases, their market value may be extremely volatile.

Leverage Risk. Leverage created by borrowing or certain types of transactions or investments may impair the Fund's liquidity, cause it to liquidate positions at an unfavorable time, increase volatility of the Fund's net asset value, or diminish the Fund's performance.

Municipal Obligations Risk. Principal and interest payments on municipal securities may not be guaranteed by the issuing body and may be payable only from a particular source. That source may not perform as expected, and payment obligations may not be made or made on time.

Portfolio Duration Risk. Portfolio duration is a measure of the expected life of a fixed-income security and its sensitivity to changes in interest rates. The longer a fund's average portfolio duration, the more sensitive the fund will be to changes in interest rates, which means funds with longer average portfolio durations may be more volatile than those with shorter durations.

Redemption and Large Transaction Risk. Ownership of the Fund's shares may be concentrated in one or a few large investors (such as funds of funds, institutional investors, and asset allocation programs) that may redeem or purchase shares in large quantities. These transactions may cause the Fund to sell securities to meet redemptions or to invest additional cash at times it would not otherwise do so, which may result in increased transaction costs, increased expenses, changes to expense ratios, and adverse effects to Fund performance. Such transactions may also accelerate the realization of taxable income if sales of portfolio securities result in gains. Moreover, reallocations by large shareholders among share classes of a fund may result in changes to the expense ratios of affected classes, which may increase the expenses paid by shareholders of the class that experienced the redemption.

Performance

The following information provides some indication of the risks of investing in the Fund. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. You may get updated performance information at www.PrincipalAM.com/mutualfundperformance.

The bar chart shows the investment returns of the Fund's Class A shares for each full calendar year of operations for 10 years (or, if shorter, the life of the Fund). These annual returns do not reflect sales charges on Class A shares; if they did, results would be lower. The table shows for the last one, five, and ten calendar year periods (or, if shorter, the life of the Fund), how the Fund's average annual total returns compare with those of one or more broad measures of market performance.

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For periods prior to the inception date of Institutional Class shares (March 10, 2015), the performance shown in the table for Institutional Class shares is that of the Fund's Class A shares, adjusted to reflect the fees and expenses of Institutional Class shares. However, where this adjustment for fees and expenses results in performance for the Institutional Class that is higher than the historical performance of the Class A shares, the historical performance of the Class A shares is used (without respect to sales charges, which does not apply to Institutional Class). These adjustments result in performance for such periods that is no higher than the historical performance of the Class A shares, which were first sold June 14, 2012.

Total Returns as of December 31

Highest return for a quarter during the period of the bar chart above:			Q4 2023			6.94%
Lowest return for a quarter during the period of the bar chart above:			Q1 2022			(8.45)%
Year-to-date return for Class A shares:			Q3 2025			1.32%

Average Annual Total Returns

For the periods ended December 31, 2024

			1 Year			5 Years			10 Years
Class A Return Before Taxes			0.45%			0.14%			2.79%
Class A Return After Taxes on Distributions			0.45%			0.14%			2.79%
Class A Return After Taxes on Distributions and Sale of Fund Shares			2.00%			0.95%			3.02%
Institutional Class Return Before Taxes			4.79%			1.19%			3.47%
Bloomberg Municipal Bond Index (reflects no deduction for fees, expenses, or taxes)			1.05%			0.99%			2.25%

After-tax returns are calculated using the historical highest 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. 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. After-tax returns are shown for Class A shares only and would be different for the other share classes.

Investment Advisor and Portfolio Managers

Principal Global Investors, LLC

•James Noble (since 2012), Portfolio Manager

•James Welch (since 2014), Portfolio Manager

Purchase and Sale of Fund Shares

Share Class			Investment Type			Purchase Minimum Per Fund
A			Initial Investment			$1,000(1)
A			Initial Investment for accounts with an Automatic Investment Plan (AIP)			$100
A			Subsequent Investments			$100(1)(2)
Institutional			There are no minimum initial or subsequent investment requirements for eligible purchasers.			N/A

(1)Some exceptions apply; see "Purchase of Fund Shares - Minimum Investments" for more information.

(2)For accounts with an AIP, the subsequent automatic investments must total $1,200 annually if the initial $1,000 minimum has not been met.

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You may purchase or redeem shares on any business day (normally any day when the New York Stock Exchange is open for regular trading) through your plan, intermediary, or Financial Professional by sending a written request to Principal Funds at P.O. Box 219971, Kansas City, MO 64121-9971 (regular mail) or 801 Pennsylvania Ave., Ste. 219971, Kansas City, MO 64105-1307 (overnight mail); calling us at 1-800-222-5852; or accessing our website (www.principal.com).

Tax Information

While the Fund intends to distribute income that is exempt from regular federal and possibly some state income taxes, a portion of the Fund's distributions may be subject to federal income taxes or to the federal individual alternative minimum tax. A portion of the Fund's distributions likely will be subject to state income taxes depending on your state's rules. Different rules may apply if you are tax exempt or if your account is tax deferred in which case your distributions would be taxed when withdrawn from the tax-deferred account.

Payments to Broker-Dealers and Other Financial Intermediaries

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

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