Amendment to Current Report (Form 8-K/A)

Mesa Air Group Files Registration Statement on Form S-4 and S-1 in Connection with Proposed Merger with Republic Airways Holdings Inc.

July 23, 2025

PHOENIX, July 23, 2025 - Mesa Air Group, Inc. (NASDAQ: MESA) ("Mesa" or the "Company") announced that it filed a registration statement on Form S-4 and S-1 with the U.S. Securities and Exchange Commission ("SEC") on July 10, 2025 in connection with the Company's proposed merger (the "Merger") with Republic Airways Holdings Inc. ("Republic"). The registration statement includes a proxy statement and preliminary prospectus. Once declared effective by the SEC, the final proxy statement/prospectus included in the Form S-4/Form S-1 will be mailed to the Mesa stockholders prior to their vote on the proposed Merger.

The registration statement has not yet become effective, and the information contained therein is subject to change. The related securities may not be sold, nor may offers to buy be accepted, prior to the time the registration statement becomes effective.

About Mesa Air Group, Inc.

Headquartered in Phoenix, Arizona, Mesa Air Group, Inc. is the holding company of Mesa Airlines, a regional air carrier providing scheduled passenger service to 82 cities in 32 states, the District of Columbia, Cuba, and Mexico. As of March 31, 2025, Mesa operated a fleet of 60 aircraft, with approximately 238 daily departures. The Company had approximately 1,650 employees. Mesa operates all its flights as United Express pursuant to the terms of a capacity purchase agreement entered into with United.