Summary Prospectus by Investment Company (Form 497K)

INTERNATIONAL EQUITY INDEX FUND

Class

Inst.

R-3

R-5

R-6

Ticker Symbol(s)

PIDIX

PIIOX

PIIQX

PFIEX

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 long-term growth of 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.

If you purchase Institutional Class or Class R-6 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.

Shareholder Fees (fees paid directly from your investment): None

Annual Fund Operating Expenses

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

			Share Class
			Inst.			R-3			R-5			R-6
Management Fees (1)			0.22%			0.22%			0.22%			0.22%
Distribution and/or Service (12b-1) Fees			N/A			0.25%			N/A			N/A
Other Expenses (2)			0.20%			0.39%			0.33%			0.07%
Acquired Fund Fees and Expenses			0.01%			0.01%			0.01%			0.01%
Total Annual Fund Operating Expenses			0.43%			0.87%			0.56%			0.30%
Expense Reimbursement (3)			(0.13)%			N/A			N/A			(0.02)%
Total Annual Fund Operating Expenses after Expense Reimbursement			0.30%			0.87%			0.56%			0.28%

(1)Fees have been restated to reflect current fees.

(2) Includes 0.01% of expenses associated with the reclaim of foreign taxes paid. The expense is not subject to the contractual expense limit.

(3) 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 0.28% for Institutional Class shares. In addition, for Class R-6, the expense limit will maintain "Other Expenses" (expressed as a percent of average net assets on an annualized basis) not to exceed 0.04% (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). 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.

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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
Institutional Class			$31			$125			$228			$530
Class R-3			89			278			482			1,073
Class R-5			57			179			313			701
Class R-6			29			94			167			379

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 28.1% 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 securities that compose the MSCI EAFE Index (the "Index"). The Index is a market-weighted equity index designed to measure the equity performance of developed markets (Europe, Australia, New Zealand, and Far East, which includes Hong Kong, Japan, and Singapore), excluding the United States and Canada. The Index includes securities of different market capitalizations (medium and large) and is rebalanced quarterly. The Fund employs a passive investment approach designed to attempt to track the performance of the Index. In seeking its objective, the Fund typically employs a replication strategy, which involves investing in the securities that make up the Index, in the same approximate proportions as the Index. The Fund will not concentrate (invest more than 25% of its assets) its investments in a particular industry except to the extent the Index is so concentrated. As of November 30, 2025, the Index was not concentrated in any industry.

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.

Equity Securities Risk. A variety of factors can negatively impact the value of equity securities held by a fund, including a decline in the issuer's financial condition, unfavorable performance of the issuer's sector or industry, or changes in response to overall market and economic conditions. A fund's principal market segment(s) (such as market capitalization or style) may underperform other market segments or the equity markets as a whole.

Foreign Currency Risk. Risks of investing in securities denominated in, or that trade in, foreign (non-U.S.) currencies include changes in foreign exchange rates and foreign exchange restrictions.

Foreign Securities Risk. The risks of foreign securities include loss of value as a result of: political or economic instability; nationalization, expropriation, or confiscatory taxation; settlement delays; and limited government regulation (including less stringent reporting, accounting, and disclosure standards than are required of U.S. companies).

Index Fund Risk. Index funds use a passive investment approach and generally do not attempt to manage market volatility, use defensive strategies, or reduce the effect of any long-term periods of poor investment performance. Therefore, the Fund may hold securities that present risks that an investment advisor researching individual securities might seek to avoid. An index fund has operating and other expenses while an index does not. As a result, over time, index funds tend to underperform the index. The correlation between fund performance and index performance may also be affected by the type of passive investment approach used by a fund (sampling or replication), changes in securities markets, changes in the composition of the index, and the timing of purchases and sales of fund shares. Errors or delays in compiling or rebalancing the Index may impact the performance of the Fund and increase transaction costs.

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Industry Concentration Risk. A fund that concentrates investments in a particular industry or group of industries has greater exposure than other funds to market, economic, and other factors affecting that industry or group of industries.

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 Institutional Class shares for each full calendar year of operations for 10 years (or, if shorter, the life of the Fund). 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.

For periods prior to the inception date of Class R-6 shares (January 3, 2017), the performance shown in the table for Class R-6 shares is that of the Fund's Institutional Class shares, adjusted to reflect the fees and expenses of Class R-6 shares. However, where this adjustment for fees and expenses results in performance for Class R-6 shares that is higher than the historical performance of the Institutional Class shares, the historical performance of the Institutional Class shares is used. These adjustments result in performance for such periods that is no higher than the historical performance of the Institutional Class shares, which were first sold December 30, 2009.

Total Returns as of December 31

Highest return for a quarter during the period of the bar chart above:			Q4 2022			18.07%
Lowest return for a quarter during the period of the bar chart above:			Q1 2020			(23.11)%
Year-to-date return for Institutional Class shares:			Q3 2025			25.80%

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Average Annual Total Returns

For the periods ended December 31, 2024

			1 Year			5 Years			10 Years
Institutional Class Return Before Taxes			3.56%			4.57%			5.04%
Institutional Class Return After Taxes on Distributions			2.41%			3.68%			4.24%
Institutional Class Return After Taxes on Distributions and Sale of Fund Shares			2.87%			3.53%			3.97%
Class R-3 Return Before Taxes			2.94%			3.98%			4.45%
Class R-5 Return Before Taxes			3.22%			4.30%			4.78%
Class R-6 Return Before Taxes			3.47%			4.59%			5.04%
MSCI EAFE NTR (reflects withholding taxes on foreign dividends, but no deduction for fees, expenses, or other taxes)			3.82%			4.73%			5.20%

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 Institutional Class shares only and would be different for the other share classes.

Investment Advisor and Portfolio Managers

Principal Global Investors, LLC

•Tyler O'Donnell (since 2023), Portfolio Manager

•Aaron J. Siebel (since 2018), Portfolio Manager

Purchase and Sale of Fund Shares

Share Class			Investment Type			Purchase Minimum Per Fund
Institutional, R-3, R-5, and R-6			There are no minimum initial or subsequent investment requirements for eligible purchasers.			N/A

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

The Fund's distributions you receive are generally subject to federal income tax as ordinary income or capital gain and may also be subject to state and local taxes, unless you are tax-exempt or 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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