FORM 10-K The Hackett Group, Inc. Securities registered pursuant to Section 12(b) of the Act: during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filingrequirements for the past 90 days.Yes☒No☐Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).Yes☒No☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer, or a smaller reporting company,or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company”, and “emerging growthcompany” in Rule 12b-2 of the Exchange Act. Large Accelerated FilerNon-accelerated FilerEmerging growth company If an emerging growthcompany, indicate by check mark if the registrant has elected not to use the extended transition period for complying with anynew or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internalcontrol over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firmthat preparedorissued its audit report.☒ If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received byany of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).Yes☐No☒The aggregate market value of the common stock held by non-affiliates of the registrant was $437,819,579on June 27, 2025 based on the last reportedsale price of the registrant’s common stock on the NASDAQ Global Market. DOCUMENTS INCORPORATED BY REFERENCE Part III of this Annual Report on Form 10-K incorporates by reference certain portions of the registrant’s proxy statement for its 2024 Annual Meeting ofShareholders to be filed with the Commission not later than 120 days after the end of the fiscal year covered by this report. CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS This Annual Report on Form 10-K and the information incorporated by reference in it include “forward-looking statements”within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934,as amended. We intend the forward-looking statements to be covered by the safe harbor provisions for forward-looking statements inthese sections. All statements regarding our expected financial position and operating results, our business strategy, our financing plansand forecasted demographic and economic trends relating to our industry are forward-looking statements. These statements cansometimes be identified by our use of forward-looking words such as “may,” “will,” “anticipate,” “estimate,” “expect,” or “intend” andsimilar expressions. These statements involve known and unknown risks, uncertainties and other factors that may cause our actualresults, performance or achievements to be materially different from the results, performance or achievements expressed or implied bythe forward-looking statements. We cannot promise you that our expectations reflected in such forward-looking statements will turn outto be correct. Factors that could impact such forward-looking statements include, among others, changes in worldwide and U.S.economic conditions that impact business confidence and the demand for our products and services, our ability to transition ourcapabilities to support generative artificial intelligence (AI)-related consulting services and solutions, our ability to effectively integrate PART I ITEM 1.BUSINESS GENERAL In this Annual Report on Form 10-K, unless the context otherwise requires, “The Hackett Group,” “Hackett,” the “Company,”“we,” “us,” and “our” refer to The Hackett Group, Inc. and its subsidiaries and predecessors. We were originally incorporated on April Our fiscal year ended December 26, 2025. OVERVIEW The Hackett Group, Inc. (NASDAQ: HCKT) is a global, IP platform-based generative artificial intelligence (“Gen AI”) strategicadvisory, business transformation, and enterprise application implementation firm. We combine proprietary benchmarking and best-practice process intelligence intellectual property ("IP") with Gen AI–enabled deli