Amendment to Supplemental Executive Retirement Plan and Trust Termination

Burke & Herbert Financial Services Corp. (the "Company") announced that its wholly-owned subsidiary, Burke & Herbert Bank & Trust Company (the "Bank"), entered into the First Amendment to the Summit Community Bank Supplemental Executive Retirement Plan and Consent to Termination of Summit Community Bank Supplemental Executive Retirement Trust (the "Amendment"). This Amendment, effective December 19, 2025, was made with H. Charles Maddy, III and other key executives of Summit Community Bank, Inc. (collectively, the "Participants"). The Amendment serves to terminate the Supplemental Executive Retirement Plan Trust ("Trust") and amend the Supplemental Executive Retirement Plan ("SERP") to waive the requirement of maintaining a "rabbi trust" in connection with the merger of Summit Community Bank, Inc. into the Bank on May 3, 2024. All other provisions of the SERP remain in effect, including the full vesting of benefits upon a change in control and the requirement for a "rabbi trust" upon a future change in control of the Bank. The termination of the Trust and return of assets to the Bank is contingent upon the written approval of 100% of the Participants.