Entry into a Material Definitive Agreement Introduction As more fully described below, on August 3, 2026, Blue Bird Corporation, a Delaware corporation (“Parent”), by and through its wholly-owned subsidiary Blue Bird Body Company, a Georgia Corporation (“BBBC”)(collectively “Blue Bird”), entered into an agreement to acquire certain assets of Detroit Chassis LLC, a Michigan limited liability company, and the longtime manufacturer of Ford Motor Company’s (“Ford”) F-53 (Class A motorhome) and F-…

Regulation FD Disclosure. On August 5, 2026, Parent issued a press release announcing the entry into the Asset Purchase Agreement with Detroit Chassis, LLC and the Master Collaboration Agreement with Ford. A copy of the press release is included with this report as Exhibit 99.1, including the presentation referenced therein, which is included with this report as Exhibit 99.2. The information included in this report under the heading “

RESULTS OF OPERATIONS AND FINANCIAL CONDITION In accordance with General Instruction B.2. to Form 8-K, the following information shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing. The information regarding the results of operations and financial conditi…

Entry into a Material Definitive Agreement On May 12, 2026, Blue Bird Body Company, a wholly-owned subsidiary of Blue Bird Corporation (the “Company”), acting solely in its capacity as plan sponsor of the Blue Bird Body Company Employee Pension Plan (the “Plan”), a frozen defined benefit pension plan that is qualified under Internal Revenue Code, entered into an agreement (the “Agreement”) with Pacific Life Insurance Company and Pacific Life & Annuity Company (collectively, “Pacific Life”) re…

RESULTS OF OPERATIONS AND FINANCIAL CONDITION In accordance with General Instruction B.2. to Form 8-K, the following information shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing. The information regarding the results of operations and financial conditi…

of the Current Report on Form 8-K of Parent filed on February 17, 2026; and (ii) the information set forth in Items 2.01, 3.02 and 5.03 of this Current Report on Form 8-K, originally filed on April 2, 2026. 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. BLUE BIRD CORPORATION By: /s/ Ted Scartz Name: Ted Scartz Title: Senior Vice President and Gene…

Class III Director — Steve Girardin: Steve Girardin was appointed as a Class III Director and will serve on the Nominating Committee.

Unregistered Sales of Equity Securities. See

Class III Director — Steve Girardin: Appointment of Steve Girardin as a Class III Director and provision for Dave Girardin's appointment if necessary.

Regulation FD Disclosure. On April 2, 2026, Parent issued a press release announcing the closing of its acquisition of the Micro Bird joint venture. A copy of the press release is furnished with this report as Exhibit 99.1. The information furnished in this report under the heading “

Completion of Acquisition or Disposition of Assets. Introduction As previously reported in its Form 8-K filed February 17, 2026, Blue Bird Corporation, a Delaware corporation (“ Parent ”), and its wholly owned subsidiary, Blue Bird Body Company, a Georgia Corporation (collectively “ Blue Bird ”), entered into an agreement to acquire the 50% interest in the Micro Bird joint venture owned by the Girardin Group. As more fully described below, this transaction closed on April 1, 2026. Micro Bird…

The filing describes an equity incentive plan amendment and restatement, which is not a management change event.

Regulation FD Disclosure. On February 17, 2026, Blue Bird issued a press release announcing its entry into a definitive agreement to acquire and consolidate the Micro Bird Joint Venture. A copy of the press release is included with this report as Exhibit 99.1, including the presentation referenced therein, which is included with this report as Exhibit 99.2. The information included in this report under the heading “

Entry into a Material Definitive Agreement Introduction As more fully described below, on February 15, 2026, Blue Bird Corporation, a Delaware corporation, by and through its wholly-owned subsidiary, Blue Bird Body Company, a Georgia Corporation (collectively “Blue Bird”) entered into an agreement to acquire the 50% interest in the Micro Bird joint venture owned by the Girardin Group. At the closing, Blue Bird will own 100% of the Micro Bird joint venture. Micro Bird Business Share Purchase A…

RESULTS OF OPERATIONS AND FINANCIAL CONDITION In accordance with General Instruction B.2. to Form 8-K, the following information shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing. The information regarding the results of operations and financial conditi…

Director — Mr. Phil Horlock: Mr. Horlock tendered his resignation from the Board of Directors.

RESULTS OF OPERATIONS AND FINANCIAL CONDITION In accordance with General Instruction B.2. to Form 8-K, the following information shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing. The information regarding the results of operations and financial conditi…

Termination of a Material Definitive Agreement. (a) On October 22, 2025, the Board of Directors (“Board”) of Blue Bird Corporation (the “Company” or “Blue Bird”), approved the termination of the previously announced joint venture agreement with Generate Capital, PBC (“Generate Capital”), respecting the joint venture named Clean Bus Solutions, LLC (the “Joint Venture” or “CBS”). Generate Capital, as the other 50% shareholder of the Joint Venture, has also approved termination of the venture, a…

Chief Operating Officer — Mr. Jeff Sanfrey: Mr. Jeff Sanfrey was promoted to Chief Operating Officer and recognized as an executive officer under SEC regulations.

Other Events. On August 5, 2025, the Board of Directors (the “Board”) of Blue Bird Corporation (the “Company”) authorized and approved a share repurchase program for up to $100 million of the currently outstanding shares of the Company’s common stock over a period up to January 1, 2028. Under the share repurchase program, the Company may repurchase shares through open market purchases, privately negotiated transactions, accelerated share repurchase transactions, block purchases or otherwise i…

RESULTS OF OPERATIONS AND FINANCIAL CONDITION In accordance with General Instruction B.2. to Form 8-K, the following information shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing. The information regarding the results of operations and financial conditi…

RESULTS OF OPERATIONS AND FINANCIAL CONDITION In accordance with General Instruction B.2. to Form 8-K, the following information shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing. The information regarding the results of operations and financial conditi…

RESULTS OF OPERATIONS AND FINANCIAL CONDITION In accordance with General Instruction B.2. to Form 8-K, the following information shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing. The information regarding the results of operations and financial conditi…

President and Chief Executive Officer — Philip Horlock: Mr. Philip Horlock is retiring as President and Chief Executive Officer.

President and CEO — Philip Horlock: Mr. Philip Horlock is retiring from his roles as President and CEO, with Mr. John F. Wyskiel appointed as the new President and CEO.