Orion Group Holdings Inc

Evaluation of Disclosure Controls and Procedures

As required, the Company’s management, with the participation of its Chief Executive Officer and Chief Financial Officer, have conducted an evaluation of the effectiveness of the Company’s disclosure controls and procedures (as such term is defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended) as of the end of the period covered by this Quarterly Report on Form 10-Q. Based on that evaluation, the Chief Executive Officer and Chief Financial Officer have concluded that the Company’s disclosure controls and procedures were effective as of September 30, 2025.

Changes in Internal Control over Financial Reporting

During the quarter ended September 30, 2025, we implemented new reporting systems and made changes to related internal controls. There have been no other changes to our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) that occurred during the quarter ended September 30, 2025 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.