☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIESEXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIESEXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROMTO Commission File Number: 001-33045 ICF International, Inc. (Exact name of Registrant as Specified in its Charter) Registrant’s telephone number, including area code: (703) 934-3000Not Applicable Securities registered pursuant to Section 12(b) of the Act. Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of theSecurities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to filesuch reports), and (2) has been subject to such filing requirements for the past 90 days.☒Yes☐No Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to besubmitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorterperiod 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, a non-accelerated filer, smallerreporting company, or an emerging growth company. See the definitions of ‘‘large accelerated filer,’’ ‘‘accelerated filer,’’ ‘‘smallerreporting company,’’ and ‘‘emerging growth company’’ in Rule 12b–2 of the Exchange Act. Large accelerated filer☒Non-accelerated filer☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition periodfor complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).☐Yes☒No As of May 1, 2026, there were 18,104,180 shares outstanding of the registrant’s common stock. ICF INTERNATIONAL, INC. AND SUBSIDIARIES QUARTERLY REPORT ON FORM 10-Q FOR THEPERIOD ENDED MARCH 31, 2026 TABLE OF CONTENTS PART I. FINANCIAL INFORMATION3Item 1.Financial Statements3Consolidated Balance Sheets at March 31, 2026 (Unaudited) and December 31, 20253Consolidated Statements of Comprehensive Income (Unaudited) for the Three Months Ended March 31, 2026and 20254Consolidated Statements of Stockholders’ Equity (Unaudited) including the Three Months Ended March 31,2026 and 20255Consolidated Statements of Cash Flows (Unaudited) for the Three Months Ended March 31, 2026 and 20256Notes to Consolidated Financial Statements7Item 2.Management’s Discussion and Analysis of Financial Condition and Results of Operations16Item 3.Quantitative and Qualitative Disclosures About Market Risk21Item 4.Controls and Procedures21PART II. OTHER INFORMATION22Item 1.Legal Proceedings22Item 1A.Risk Factors22Item 2.Unregistered Sales of Equity Securities, Use of Proceeds, and Issuer Purchases of Equity Securities22Item 3.Defaults Upon Senior Securities22Item 4.Mine Safety Disclosures22Item 5.Other Information22Item 6.Exhibits23 ICF International, Inc. and SubsidiariesCONSOLIDATED BALANCE SHEETS March 31, 2026(in thousands, except share and per share amounts)(Unaudited)December 31, 2025ASSETSCash and cash equivalents$3,883$5,297Restricted cash49,35747,984Accounts receivable, net239,999237,996Contract assets192,231186,684Prepaid expenses and other current assets19,92018,390Income tax receivable19,05518,087Total Current Assets524,445514,438Property and Equipment, net55,39358,357Goodwill1,251,4271,252,207Other intangible assets, net73,64481,555Operating lease - right-of-use assets102,844106,274Other assets45,22337,340Total Assets$2,052,976$2,050,171 LIABILITIES AND STOCKHOLDERS’ EQUITYAccounts payable Stockholders’ Equity:Preferred stock, par value $.001; 5,000,000shares authorized; noneissued——Common stock, par value $.001; 70,000,000shares authorized; 24,513,156and24,378,749shares issued at March 31, 2026 and December 31, 2025, respectively;18,117,062and 18,247,837shares outstanding at March 31, 2026 and December 31, 2025,respectively2424Additional paid-in capital470,476465,779Retained earnings974,042956,077Treasury stock, 6,396,094and 6,130,912shares at March 31, 2026 and December 31, 2025,respectively(398,536)(379,970)Accumulated other comprehensive loss(14,097)(13,428)Total Stockholders’ Equity1,031,9091,028,482Total Liabilities and Stockholders’ Equity$2,052,976$2,050,171 ICF International, Inc. and SubsidiariesCONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME(UNAUDITED) ICF International, Inc. and SubsidiariesCONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY(UNAUDITED) ICF International, Inc. and SubsidiariesCONSOLIDATED STATEMENTS OF CASH FLOWS(UNAUDITED) ICF International, Inc. and SubsidiariesNotes to Consolidated Financial Statements(Unaudited)(dollar amounts in tables in thousands, except share an