Phoenix Energy One LLC Series A Pfd美股招股说明书(2026-08-17版)

PHOENIX ENERGY ONE, LLC This prospectus supplement updates, amends, and supplements (i) the prospectus, dated May 4, 2026 (as updated, amended, and supplemented to date, the“Unsecured Notes Prospectus”), which forms a part of our Registration Statement on Form S-1 (Registration No. 333-282862), and (ii) the prospectus, dated July 7,2026 (as updated, amended, and supplemented to date, the “Secured Notes Prospectus” and, together with the Unsecured Prospectus, the “Prospectuses”), whichforms a part of our Registration Statement on Form S-1 (Registration No. 333-296428). Capitalized terms used in this prospectus supplement and not otherwisedefined herein have the meanings specified in the Unsecured Notes Prospectus or Secured Notes Prospectus, as applicable. This prospectus supplement is being filed to update, amend, and supplement the information included in each of the Prospectuses with the informationcontained in our Current Report on Form 8-K, filed with the SEC on August 17, 2026, which is set forth below. This prospectus supplement is not complete without the applicable Prospectus. This prospectus supplement should be read in conjunction with each of theProspectuses, which is to be delivered with this prospectus supplement, and is qualified by reference thereto, except to the extent that the information in thisprospectus supplement updates or supersedes the information contained in the applicable Prospectus. Please keep this prospectus supplement with the applicableProspectus for future reference. Investing in the Notes involves risks. See “Risk Factors” beginning on page 27 of the UnsecuredNotes Prospectus and on page 29 of the Secured Notes Prospectus. Neither the U.S. Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passedupon the adequacy or accuracy of this prospectus supplement or the accompanying Prospectus. Any representation to the contrary is a criminal offense. The date of this prospectus supplement is August 17, 2026. UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORTPursuant to Section 13 or 15(d)of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 12, 2026 Phoenix Energy One, LLC(Exact name of registrant as specified in its charter) 001-42868(Commission File Number) Delaware(State or other jurisdiction of incorporation)18575 Jamboree Road, Suite 830Irvine, CA(Address of principal executive offices) (I.R.S. Employer Identification No.) 92612(Zip Code) Registrant’s telephone number, including area code: (949) 416-5037 Not Applicable(Former name or former address, if changed since last report) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligationof the registrant under any of the following provisions: Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) 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 ofthis chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying withany new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Item 1.01 Entry into a Material Definitive Agreement. As previously disclosed, on August 12, 2024, Phoenix Energy One, LLC (the “Company”) entered into that certain Amendedand Restated Senior Secured Credit Agreement with Phoenix Operating LLC, as borrower (“Phoenix Operating”), each of thelenders from time to time party thereto, and Fortress Credit Corp. (“Fortress”), as administrative agent for the lenders (as amendedor supplemented from time to time, including by Amendment No. 10 (as defined below), the “Credit Agreement”). Terms usedherein but not defined herein shall have the meaning given to such terms in the Credit Agreement. On August 12, 2026 (the “Amendment No. 10 Effective Date”), the Company, Phoenix Operating, the Guarantors partythereto, the Specified Additional Guarantor, the Lenders party thereto, and Fortress, as administrative agent and as collateral agentfor the Lenders, entered into that certain Amendment No. 10 to Amended and Restated Senior Secured Credit Agreement(“Amendment No. 10”). Amendment No. 10, among other things, established $75 million aggregate principal amount inAmendment No. 7 Discretiona