HERITAGE FINANCIAL CORP /WA/

(a) Evaluation of Disclosure Controls and Procedures

Our management has evaluated, with the participation and under the supervision of our Chief Executive Officer (the Company’s principal executive officer) and Chief Financial Officer (the Company’s principal financial officer), the effectiveness of our disclosure controls and procedures (as defined in Rule 13a-15(e) of the Exchange Act) as of the end of the period covered by this report. Based on this evaluation, our Chief Executive Officer and Chief Financial Officer have concluded that, as of such date, the Company’s disclosure controls and procedures were effective to provide reasonable assurance that that information required to be disclosed in reports that it files under the Exchange Act is (1) recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms, and (2) accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate to allow timely decisions regarding required disclosure.

(b) Changes in Internal Control Over Financial Reporting

There have been no changes in the Company’s internal control over financial reporting (as defined in Rule 13a-15(f) of the Exchange Act) that occurred during the three months ended September 30, 2025 that have materially affected, or are reasonably likely to materially affect, the Company’s internal control over financial reporting.