CRA INTERNATIONAL INC

Report of Independent Registered Public Accounting Firm

Board of Directors and Shareholders

Opinion on the financial statements

We have audited the accompanying consolidated balance sheets of CRA International, Inc. (a Massachusetts corporation) and subsidiaries (the “Company”) as of December 28, 2024, and December 30, 2023, the related consolidated statements of operations, comprehensive income, shareholders’ equity, and cash flows for each of the three years in the period ended December 28, 2024, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 28, 2024, and December 30, 2023, and the results of its operations and its cash flows for each of the three years in the period ended December 28, 2024, in conformity with accounting principles generally accepted in the United States of America.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (“PCAOB”), the Company’s internal control over financial reporting as of December 28, 2024, based on criteria established in the 2013 Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (“COSO”), and our report dated February 20, 2025, expressed an unqualified opinion.

Basis for opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Change in accounting principle

As discussed in Note 1 to the consolidated financial statements, the Company has adopted new accounting guidance in 2024 related to the disclosure of segment information in accordance with ASU 2023-07, Segment Reporting (Topic 280). The adoption was retrospectively applied to 2023 and 2022.

Critical audit matter

The critical audit matter communicated below is a matter arising from the current period audit of the financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Fixed-Price Revenue Recognition – Estimates of total costs to complete a performance obligation for performance obligations that are partially satisfied as of the balance sheet date

As described further in Notes 1 and 2 to the consolidated financial statements, the Company recognizes revenue from fixed-price arrangements using the ratio of costs incurred to total estimated costs for completing a performance obligation. We identified the Company’s estimates of total costs to complete a performance obligation for performance obligations in a fixed-price arrangement that are partially satisfied at the balance sheet date as a critical audit matter.

The principal considerations for our determination that the Company’s estimates of total costs to complete a performance obligation for performance obligations in a fixed-price arrangement that are partially satisfied at the balance sheet date is a critical audit matter are the significant management judgement in estimating forecasted direct labor, subcontract labor and other direct costs remaining to complete a performance obligation and to determine the related revenue recognized. Significant

FS-2 management estimates are subject to estimation uncertainty and require significant auditor subjectivity in evaluating the results of our procedures and the reasonableness of those estimates.

Our audit procedures related to the estimates of total costs to complete a performance obligation for performance obligations in a fixed-price arrangement that are partially satisfied at the balance sheet date included the following, among others.

•We tested the design and operating effectiveness of internal controls relating to management’s estimates of total costs to complete a performance obligation in a fixed-price arrangement for partially completed performance obligations as of the balance sheet date.

•We evaluated management’s historical ability to estimate total costs to complete a performance obligation.

•For a sample of fixed-price arrangements, that had partially completed performance obligations as of the balance sheet date, we obtained subsequent actual costs incurred and subsequent estimates of total costs to complete and compared to the Company's estimate at the balance sheet date.

/s/GRANT THORNTON LLP

We have served as the Company's auditor since 2020.

Boston, Massachusetts

February 20, 2025

FS-3