COSTAR GROUP, INC.

We maintain disclosure controls and procedures designed to ensure that information required to be disclosed in our reports filed or submitted under the Exchange Act is recorded, processed, summarized, and reported within the time periods specified in the SEC’s rules and forms. These controls also are designed to ensure that such information is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate, to allow for timely decisions regarding required disclosure. In designing and evaluating the disclosure controls and procedures, management recognizes that any systems of controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives. Accordingly, management is required to apply judgment in evaluating the cost-benefit relationship of possible controls and procedures.

As of June 30, 2026, under the supervision and with the participation of our management, including our Chief Executive Officer and our Chief Financial Officer, we evaluated the effectiveness of our disclosure controls and procedures. Based on this evaluation, our Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures were effective as of June 30, 2026, and were operating at a reasonable assurance level.

We are continuing to integrate the internal controls over financial reporting of recent acquisitions. These activities may require modifications to certain processes, systems, and other components of internal controls over financial reporting. Consistent with our process changes, we evaluate the design and effectiveness of the internal controls as part of our overall assessment of disclosure controls and procedures.

Other than the integration activities associated with recent acquisitions, there were no changes in our internal control over financial reporting during our most recent fiscal quarter that have materially affected or are reasonably likely to materially affect our internal control over financial reporting.

PART II — OTHER INFORMATION