Principal Diversified Select Real Asset Fund

Supplement dated March 20, 2023

to the Prospectus and Statement of Additional Information

both dated August 1, 2022

(as previously supplemented)

This supplement updates information currently in the Prospectus and Statement of Additional Information. Please retain this supplement for future reference.

The changes described below are being made to the Principal Diversified Select Real Asset Fund’s Prospectus.

FEE TABLE AND SUMMARY

Delete the reference to Tortoise Capital Advisors, L.L.C.

MANAGEMENT OF THE FUND

Delete all references to Tortoise Capital Advisors, L.L.C.

The changes described below are being made to the Principal Diversified Select Real Asset Fund’s Statement of Additional Information.

INVESTMENT ADVISORY AND OTHER SERVICES

Delete all references to Tortoise Capital Advisors, L.L.C.

APPENDIX B – PROXY VOTING POLICIES

Delete the proxy voting policy for Tortoise Capital Advisors, L.L.C.

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