Document

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 and other information about the Fund online at www.principalfunds.com/prospectuses. You can also get this information at no cost by calling 1-800-222-5852 or by sending an email request to prospectus@principalfunds.com.

This Summary prospectus incorporates by reference the Statutory Prospectus dated June 15, 2018, as supplemented on June 25, 2018, July 13, 2018, September 17, 2018, September 28, 2018, October 9, 2018, October 29, 2018, November 30, 2018, and December 17, 2018 and the Statement of Additional Information dated June 15, 2018, as supplemented on June 25, 2018, July 30, 2018, September 17, 2018, September 28, 2018, October 9, 2018, October 29, 2018, November 30, 2018, and December 17, 2018 (which may be obtained in the same manner as the Prospectus).

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Class A shares of Principal Funds, Inc. More information about these and other discounts is available from your financial professional and in “Choosing a Share Class and The Costs of Investing” beginning on page 130 of the Fund’s prospectus, Appendix C to the prospectus titled "Intermediary-Specific Sales Charge Waivers and Reductions", and “Multiple Class Structure” beginning on page 4 of the Fund’s Statement of Additional Information.



	Share Class
	A	C	Inst.	R-6
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.50%	None	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the offering price or NAV at the time Sales Load is paid, whichever is less)	1.00%	1.00%	None	None



	Share Class
	A	C	Inst.	R-6
Management Fees	0.76%	0.76%	0.76%	0.76%
Distribution and/or Service (12b-1) Fees	0.25%	1.00%	N/A	N/A
Other Expenses	0.16%	0.16%	0.13%	0.02%
Acquired Fund Fees and Expenses	0.23%	0.23%	0.23%	0.23%
Total Annual Fund Operating Expenses	1.40%	2.15%	1.12%	1.01%
Expense Reimbursement ⁽¹⁾	(0.04)%	(0.04)%	(0.03)%	—%
Total Annual Fund Operating Expenses after Expense Reimbursement	1.36%	2.11%	1.09%	1.01%



⁽¹⁾	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, 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 1.13% for Class A, 1.88% for Class C and 0.86% 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 0.02%, (excluding interest expense, expenses related to fund investments, acquired fund fees and expenses, and other extraordinary expenses). It is expected that the expense limits will continue through the period ending December 30, 2019; 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.

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:

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 annualized portfolio turnover rate was 25.5% of the average value of its portfolio.

Under normal circumstances, the Fund invests at least 80% of its net assets, plus any borrowings for investment purposes, in dividend-paying equity securities of companies with small to medium market capitalizations at the time of purchase. For this Fund, companies with small to medium market capitalizations are those with market capitalizations similar to companies in the Russell 2500 Value Index (as of April 30, 2018, the range of the index was between approximately $16.8 million and $16.2 billion). The Fund invests in value equity securities, an investment strategy that emphasizes buying equity securities that appear to be undervalued. The Fund invests in the securities of foreign issuers, real estate investment trusts, preferred securities, convertible securities, master limited partnerships, and royalty trusts.

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, in alphabetical order, are:

Convertible Securities Risk. Convertible securities are securities that are convertible into common stock. Convertible securities are subject to credit and interest rate risks associated with fixed-income securities and to stock market risk associated with equity securities.

Equity Securities Risk. The value of equity securities could decline if the issuer’s financial condition declines or 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 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).

Master Limited Partnership ("MLP") Risk. MLPs are publicly-traded limited partnership interests or units. An MLP that invests in a particular industry (e.g., oil and gas) will be harmed by detrimental economic events within that industry. As partnerships, MLPs may be subject to less regulation (and less protection for investors) under state laws than corporations. In addition, MLPs may be subject to state taxation in certain jurisdictions, which may reduce the amount of income an MLP pays to its investors.

Preferred Securities Risk. Because preferred securities have a lower priority claim on assets or earnings than senior bonds and other debt instruments in a company's capital structure, they are subject to greater credit and liquidation risk than more senior debt instruments. In addition, preferred securities are subject to other risks, such as limited or no voting rights, deferring or skipping distributions, interest rate risk, and redeeming the security prior to any stated maturity date.

Real Estate Investment Trusts (“REITs”) Risk. In addition to risks associated with investing in real estate securities, REITs are dependent upon management skills, are not diversified, and are subject to heavy cash flow dependency, risks of default by borrowers, and self-liquidation. Investment in REITs also involves risks similar to risks of investing in small market capitalization companies, such as limited financial resources, less frequent and limited volume trading, and may be subject to more abrupt or erratic price movements than larger company securities. A REIT could fail to qualify for tax-free pass-through of income under the Internal Revenue Code. Fund shareholders will indirectly bear their proportionate share of the expenses of REITs in which the fund invests.

Real Estate Securities Risk. Investing in real estate securities subjects the fund to the risks associated with the real estate market (which are similar to the risks associated with direct ownership in real estate), including declines in real estate values, loss due to casualty or condemnation, property taxes, interest rate changes, increased expenses, cash flow of underlying real estate assets, regulatory changes (including zoning, land use and rents), and environmental problems, as well as to the risks related to the management skill and creditworthiness of the issuer.

Redemption Risk. A fund that serves as an underlying fund for a fund of funds is subject to certain risks. When a fund of funds reallocates or rebalances its investments, an underlying fund may experience relatively large redemptions or investments. These transactions may cause the underlying fund to sell portfolio securities to meet such redemptions, or to invest cash from such investments, at times it would not otherwise do so, and may as a result increase transaction costs, result in changes to expense ratios and increased expenses, and adversely affect underlying fund performance. Moreover, a fund of fund’s redemptions or reallocations among share classes of an underlying 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.

Royalty Trust Risk. Royalty trust revenues and cash flows could be adversely affected by a sustained decline in demand for natural resource and related products resulting from a recession or other adverse economic conditions, an increase in the market price of the underlying commodity, higher taxes or other regulatory actions that increase costs, a shift in consumer demand, or other conditions. Rising interest rates could adversely affect the performance, and limit the capital appreciation, of royalty trusts because of the increased availability of alternative investments at more competitive yields. Fund shareholders will indirectly bear their proportionate share of the royalty trusts' expenses.

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 by calling 1-800-222-5852 or online at www.principalfunds.com.

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.

For periods prior to the inception date of Class C shares (June 14, 2012) and Class R-6 shares (January 3, 2017), the performance shown in the table for these newer classes is that of the Fund's Institutional Class shares, adjusted to reflect the respective fees and expenses of each class. However, where this adjustment for fees and expenses results in performance for a newer class 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 on June 6, 2011.



Average Annual Total Returns
For the periods ended December 31, 2017	1 Year	5 Year	Life of Fund
Class A Return Before Taxes	6.74%	13.11%	12.09%
Class A Return After Taxes on Distributions	5.28%	11.84%	10.92%
Class A Return After Taxes on Distributions and Sale of Fund Shares	4.79%	10.15%	9.45%
Class C Return Before Taxes	11.15%	13.50%	12.15%
Institutional Class Return Before Taxes	13.30%	14.82%	13.50%
Class R-6 Return Before Taxes	13.35%	14.78%	13.43%
Russell 2500 Value Index (reflects no deduction for fees, expenses, or taxes)	10.36%	13.27%	11.85%

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.

Purchase and Sale of Fund Shares



Share Class	Investment Type	Purchase Minimum Per Fund
A and C	Initial Investment	$1,000⁽¹⁾
A and C	Initial Investment for accounts with an Automatic Investment Plan (AIP)	$100
A and C	Subsequent Investments	$100⁽¹⁾⁽²⁾
Institutional and R-6	There are no minimum initial or subsequent investment requirements for eligible purchasers.	N/A

For retail investors (i.e., non-employer sponsored retirement plan investors), effective as of the close of the New York Stock Exchange on December 1, 2016, and for employer-sponsored retirement plan investors, effective as of the close of the New York Stock Exchange on January 6, 2017, the Small-MidCap Dividend Income Fund will no longer be available for purchases from new investors except in limited circumstances. See the section Purchase of Fund Shares for additional information.

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 430 W. 7th Street, Ste. 219971, Kansas City, MO 64105-1407 (overnight mail); calling us at 1-800-222-5852; or accessing our website (www.principalfunds.com).

Class C shares are subject to a 10-year automatic conversion plan whereby Class C shares held for ten years after purchase will automatically convert to Class A shares of the same Fund. See “Purchase of Fund Shares” in the Prospectus for more 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.

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank, insurance company, investment adviser, etc.), 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.



Class	A	C	Inst.	R-6
Ticker Symbol(s)	PMDAX	PMDDX	PMDIX	PMDHX



	1 year	3 years	5 years	10 years
Class A	$681	$965	$1,270	$2,134
Class C	314	669	1,151	2,480
Institutional Class	111	353	614	1,360
Class R-6	103	322	558	1,236



	1 year	3 years	5 years	10 years
Class C	$214	$669	$1,151	$2,480



Highest return for a quarter during the period of the bar chart above:	Q1 '13	12.32%
Lowest return for a quarter during the period of the bar chart above:	Q3 '15	(8.49)%


Objective:	The Fund seeks to provide current income and long-term growth of income and capital.


•	Small and Medium Market Capitalization Companies. Investments in small and medium sized companies may involve greater risk and price volatility than investments in larger, more mature companies.


⁽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.


•	Daniel R. Coleman (since 2011), Portfolio Manager


•	Sarah E. Radecki (since 2018), Portfolio Manager


•	David W. Simpson (since 2011), Portfolio Manager