Filed Pursuant to Rule 424(b)(3)

Registration No. 333-261904

Prospectus Supplement No. 9

(To Prospectus dated November 10, 2022)

P3 Health Partners, Inc.

240,855,865 Shares of Class A Common Stock

267,329 Warrants to Purchase Shares of Class A Common Stock

10,819,105 Shares of Class A Common Stock underlying Warrants

This prospectus supplement updates, amends and supplements the prospectus dated November 10, 2022 (the “Prospectus”), relating to the resale of up to 240,855,865 shares of our Class A Common Stock by the selling securityholders named in the prospectus (including their pledgees, donees, transferees or other successors-in-interest), the resale of up to 267,329 warrants to purchase shares of Class A Common Stock and the issuance by us of up to 10,819,105 shares of Class A Common Stock upon the exercise of outstanding warrants, which forms a part of our Registration Statement on Form S-1 (Registration No. 333-261904).

This prospectus supplement is being filed to update, amend and supplement the Prospectus with the information contained in our Current Report on Form 8-K filed with the SEC on April 25, 2023, which is set forth below.

This prospectus supplement is not complete without the Prospectus. This prospectus supplement should be read in conjunction with the Prospectus, which is to be delivered with this prospectus supplement, and is qualified by reference thereto, except to the extent that the information in this prospectus supplement updates or supersedes the information contained in the Prospectus. Please keep this prospectus supplement with your Prospectus for future reference.

Our Class A Common Stock is listed on the Nasdaq Stock Market (“Nasdaq”) under the symbol “PIII” and our warrants are listed on Nasdaq under the symbol “PIIIW”. On April 24, 2023, the closing sale price of our Class A Common Stock was $1.10 per share and the closing price of our warrants was $0.0643 per warrant.

INVESTING IN OUR SECURITIES INVOLVES RISKS THAT ARE DESCRIBED IN THE “RISK FACTORS” SECTION BEGINNING ON PAGE 6 OF THE PROSPECTUS.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus supplement or the Prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is April 25, 2023.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(D)

OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): April 25, 2023

P3 Health Partners Inc.

(Exact name of registrant as specified in its charter)

(702) 910-3950

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company x

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 8.01. Other Events.

The Board of Directors of P3 Health Partners Inc. (the “Company”) has established July 24, 2023 as the date of the Company’s 2023 Annual Meeting of Stockholders (the “2023 Annual Meeting”). The 2023 Annual Meeting will be held virtually by means of remote communication. The details of the virtual annual meeting, including how stockholders can log into the virtual meeting, vote and submit questions, will be disclosed in the Company’s definitive proxy statement for the 2023 Annual Meeting to be filed with the Securities and Exchange Commission.

Any stockholder seeking to bring business before the 2023 Annual Meeting or to nominate a director must provide timely notice, as set forth in the Company’s Bylaws (the “Bylaws”). Specifically, written notice of any proposed business or nomination must be received at the Company’s principal executive offices no later than May 5, 2023 (which is the tenth day following this public announcement of the date of the 2023 Annual Meeting). Any notice of proposed business or nomination must comply with the specific requirements set forth in the Bylaws. In addition to satisfying the requirements under the Bylaws, to comply with the universal proxy rules, stockholders who intend to solicit proxies in support of director nominees other than the Company’s nominees must provide notice that sets forth the information required by Rule 14a-19 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”).

Stockholders who intend to have a proposal considered for inclusion in the Company’s 2023 proxy materials for presentation at its 2023 Annual Meeting pursuant to Rule 14a-8 under the Exchange Act must submit the proposal in writing to the Company’s Corporate Secretary at its principal executive offices by May 5, 2023.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.