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): March 4, 2025

MESA AIR GROUP, INC.

(Exact name of registrant as specified in its charter)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of 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 of this 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 with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. 

Item 4.01. Changes in Registrant’s Certifying Accountant.

On November 1, 2024, CBIZ CPAs P.C. (“CBIZ”) acquired the attest business of Marcum LLP (“Marcum”), the present independent registered public accounting firm of Mesa Air Group, Inc (the “Company”). As a result of the acquisition of the Marcum attestation business, on March 4, 2025, the Company was notified by Marcum that Marcum will resign as the Company’s independent registered public accounting firm effective immediately upon the filing of the Company’s Form 10-K for the fiscal year ended September 30, 2024. Concurrently with the Marcum notification, on March 4, 2025, the Company, with the approval of the Audit Committee of the Company’s Board of Directors (the “Board”), has engaged CBIZ as the Company’s independent registered public accounting firm for the fiscal year ending September 30, 2025.

During the period April 12, 2024 through March 4, 2025, the date Marcum informed the Company of their resignation, there were (a) no “disagreements” (as defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions) with Marcum on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure, which disagreements, if not resolved to the satisfaction of Marcum, would have caused Marcum to make reference to such disagreement in its report and (b) no “reportable events” (as defined in Item 304(a)(1)(v) of Regulation S-K and the related instructions).

During the period April 12, 2024 through March 4, 2025, the date Marcum informed the Company of their resignation, neither the Company nor anyone on the Company's behalf consulted with CBIZ regarding (i) the application of accounting principles to a specific completed or contemplated transaction or regarding the type of audit opinions that might be rendered by CBIZ on the Company’s financial statements, and CBIZ did not provide any written or oral advice that was an important factor considered by the Company in reaching a decision as to any such accounting, auditing, or financial reporting issue or (ii) any matter that was either the subject of a disagreement (as defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions), as that term is described in Item 304(a)(1)(iv) of Regulation S-K, or a reportable event, as that term is defined in Item 304(a)(1)(v) of Regulation S-K.

The Company provided Marcum with a copy of this Current Report on Form 8-K prior to its filing with the U.S. Securities and Exchange Commission (the “SEC”) and requested that Marcum furnish the Company with a letter addressed to the SEC, pursuant to Item 304(a)(3) of Regulation S-K, stating whether it agrees with the above statements and, if it does not agree, the respects in which it does not agree. A copy of the letter, dated March 4, 2025, is filed as Exhibit 16.1 (which is incorporated by reference herein) to this Current Report on Form 8-K.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

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.