Ameresco, Inc.

AMENDMENT NO. 1 TO 2020 STOCK INCENTIVE PLAN

WHEREAS, Ameresco, Inc. (the “Company”) maintains the 2020 Stock Incentive Plan (the “Plan”);

WHEREAS, the Board of Directors of the Company has determined that it is in the best interest of the Company and its stockholders to amend the Plan, pursuant to Section 12(d) thereof, to increase the number of shares of Class A common stock, $0.0001 par value per share, of the Company that may be granted under the Plan;

NOW, THEREFORE, in consideration of the foregoing, the Plan is amended, pursuant to Section 12(d) thereof, as follows:

Section 4(a)(1) is deleted and replaced in its entirety with the following:

“(1)Authorized Number of Shares. Subject to adjustment under Section 10, Awards may be made under the Plan (any or all of which Awards may be in the form of Incentive Stock Options, as defined in Section 5(b)) for up to eight million two hundred thousand (8,200,000) shares of Class A common stock. Shares issued under the Plan may consist in whole or in part of authorized but unissued shares or treasury shares.”

Except as set forth above, all other terms of the Plan shall remain unchanged and in full force and effect. Capitalized terms used herein and not otherwise defined herein shall have the respective meanings assigned to them in the Plan.

This Amendment was adopted by the Board of Directors of the Company on February 10, 2026.