Executive Vice President and General Counsel — David J. Corrsin: The Executive Vice President and General Counsel is retiring from his officer and director roles but will continue to serve as a Special Legal Advisor, indicating an orderly transition rather than a sudden loss of key personnel.

CFO — Mark A. Chiplock: The CFO is resigning to pursue other opportunities, and the company has not yet named a successor, creating a leadership vacuum.

Results of Operations and Financial Condition. On August 3, 2026, the Company announced its financial results for the quarter ended June 30, 2026. The Company also posted supplemental information with respect to its quarter ended June 30, 2026 results on the Investor Relations section of its website at www.ameresco.com. The press release and the supplemental information issued in connection with the announcement are furnished as Exhibit 99.1 and Exhibit 99.2, respectively, to this Current Rep…

Director — Brian Cox: Brian Cox was appointed as a class III director of Ameresco, Inc.

The filing describes an amendment to the equity incentive plan, not a management change.

Entry into a Material Definitive Agreement. The information included in the Explanatory Note above is incorporated by reference herein. On the Closing Date, pursuant to the Contribution Agreement, the Joint Venture, AMRC Biogas HoldCo and JV Investor entered into an amended and restated limited liability company agreement of the Joint Venture (the “JV Agreement”). A summary of the material terms of the JV Agreement, including with respect to quarterly and liquidating distributions, AMRC Bioga…

Completion of Acquisition or Disposition of Assets. The information contained in the Explanatory Note to this Current Report on Form 8-K, is incorporated herein by reference into this

of Form 8-K. The sole purpose of this Amendment is to file as an exhibit the Contribution Agreement that was described in the Original Report. Except as described in this Amendment, the information in the Original Report remains unchanged, and this Amendment does not provide any additional information or update any disclosures contained in the Original Report.

Entry into a Material Definitive Agreement As previously announced, on May 4, 2026 , Ameresco, Inc., a Delaware corporation (“we,” the “Company,” or “Ameresco”), through certain of its subsidiaries, including Ameresco Biogas HoldCo LLC (“AMRC Biogas HoldCo”), entered into a contribution and equity purchase agreement (the “Contribution Agreement” and, the transactions contemplated thereby, the “JV Transaction”) with an affiliate of HA Sustainable Infrastructure Capital, Inc., a Delaware corpor…

The issuance of the Class B Units to JV Investor will be made in reliance upon the exemption from the registration requirements of the Securities Act of 1933, as amended (the “Securities Act”), provided by Section 4(a)(2) thereof as a transaction by an issuer not involving any public offering.

Results of Operations and Financial Condition. On May 4, 2026 , the Company announced its financial results for the quarter ended March 31, 2026. The Company also posted supplemental information with respect to its quarter ended March 31, 2026 results on the Investor Relations section of its website at www.ameresco.com. The press release and the supplemental information issued in connection with the announcement are furnished as Exhibit 99.1 and Exhibit 99.2, respectively, to this Current Rep…

Chief Executive Officer — Mr. Bakas: Mr. Bakas is being promoted to CEO of the Joint Venture.

Co-President, Chief Operating Officer — Ms. Nicole A. Bulgarino, Mr. Louis P. Maltezos, Mr. Peter Christakis: Internal promotions and role expansions within the company.

Entry into a Material Definitive Agreement On March 30, 2026 , Ameresco, Inc. ("Ameresco" or the "Company") entered into Amendment No. 2 (“Amendment No. 2”) to the Sixth Amended and Restated Credit Agreement (the “Senior Secured Loan Agreement”) by and among the Company, Bank of America, N.A., as administrative agent, the lenders party thereto, BOFA Securities, Inc., KeyBanc National Association and Cooperative Robobank U.S., as joint lead arrangers and joint bookrunners, and Webster Bank N.A…

Creation of a Direct Financial Obligation or an Obligation Under an Off-Balance Sheet Arrangement. The discussion in

Results of Operations and Financial Condition. On March 2, 2026, Ameresco, Inc. (“we” or the “Company”) announced its financial results for the quarter and fiscal year ended December 31, 2025. The Company also posted supplemental information with respect to its fourth quarter and full year results on the Investor Relations section of its website at www.ameresco.com. The press release and the supplemental information issued in connection with the announcement are furnished as Exhibit 99.1 and…

Results of Operations and Financial Condition. On November 3, 2025 , Ameresco, Inc. (“we” or the “Company”) announced its financial results for the quarter ended September 30, 2025. The Company also posted supplemental information with respect to its quarter ended September 30, 2025 results on the Investor Relations section of its website at www.ameresco.com. The press release and the supplemental information issued in connection with the announcement are furnished as Exhibit 99.1 and Exhibit…

Results of Operations and Financial Condition. On August 4, 2025 , Ameresco, Inc. (“we” or the “Company”) announced its financial results for the quarter ended June 30, 2025. The Company also posted supplemental information with respect to its quarter ended June 30, 2025 results on the Investor Relations section of its website at www.ameresco.com. The press release and the supplemental information issued in connection with the announcement are furnished as Exhibit 99.1 and Exhibit 99.2, respe…

Results of Operations and Financial Condition. On May 5, 2025 , Ameresco, Inc. (“we” or the “Company”) announced its financial results for the quarter ended March 31, 2025. The Company also posted supplemental information with respect to its quarter ended March 31, 2025 results on the Investor Relations section of its website at www.ameresco.com. The press release and the supplemental information issued in connection with the announcement are furnished as Exhibit 99.1 and Exhibit 99.2, respec…

Results of Operations and Financial Condition. On February 27, 2025, Ameresco, Inc. (“we” or the “Company”) announced its financial results for the quarter and fiscal year ended December 31, 2024. The Company also posted supplemental information with respect to its fourth quarter and full year results on the Investor Relations section of its website at www.ameresco.com. The press release and the supplemental information issued in connection with the announcement are furnished as Exhibit 99.1…

Entry into a Material Definitive Agreement Sixth Amended and Restated Senior Secured Credit Agreement On January 23, 2025 , Ameresco, Inc. ("Ameresco" or the "Company") refinanced its term loan and revolving credit facility by enteri ng into a sixth amended and restated senior secured credit agreement with the lenders party thereto, BOFA Securities, Inc., KeyBanc National Association and Cooperative Robobank U.S., as joint lead arrangers and joint bookrunners, Webster Bank N.A. and HSBC Bank…

Creation of a Direct Financial Obligation or an Obligation Under an Off-Balance Sheet Arrangement. The discussion in

Results of Operations and Financial Condition. On November 7, 2024 , Ameresco, Inc. (“we” or the “Company”) announced its financial results for the quarter ended September 30, 2024. The Company also posted supplemental information with respect to its quarter ended September 30, 2024 results on the Investor Relations section of its website at www.ameresco.com. The press release and the supplemental information issued in connection with the announcement are furnished as Exhibit 99.1 and Exhibit…

of this Current Report on Form 8-K, including Exhibit 99.1 attached hereto, is intended to be furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing. Forwar…

Chief Financial Officer — Mark Chiplock: Mr. Chiplock was promoted to Chief Financial Officer, succeeding Mr. Hole who is leaving the company.