克利尔沃特纸业 2025年度报告

FORM 11-K ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACTOF 1934 For the fiscal year ended December31, 2025OR TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGEACT OF 1934 For the transition period fromtoCommission file number001-34146 A.Full title of the plan and the address of the plan, if different from that of the issuer named below: Clearwater Paper 401(k) Plan Name of issuer of the securities held pursuant to the plan and the address of its principal executive office: CLEARWATER PAPER CORPORATION601 West Riverside Avenue, Suite 300Spokane, Washington 99201 Financial Statements and Supplemental ScheduleYears ended December31, 2025 and 2024 CLEARWATER PAPER 401(k)PLAN Table of Contents Page(s)Report of Independent Registered Public Accounting Firm1Statements of Net Assets Available for Benefits2Statements of Changes in Net Assets Available for Benefits3Notes to Financial Statements4Supplemental Schedule(Attachments to Form 5500)ScheduleH, Part IV, Line4(i) – Schedule of Assets (Held at End of Year)11Exhibit Index12Signature13 Report of Independent Registered Public Accounting Firm To the Benefits Committee of theClearwater Paper 401(k) PlanSpokane, Washington Opinion on the Financial Statements We have audited the accompanying statements of net assets available for benefits of the Clearwater Paper 401(k) Plan(the “Plan”) as of December 31, 2025 and 2024, the related statements of changes in net assets available for benefits forthe years then ended, and the related notes (collectively referred to as thefinancial statements). In our opinion, thefinancial statements present fairly, in all material respects, the net assets available for benefits of the Plan as of December31, 2025 and 2024, and the changes in net assets available for benefits for the years then ended, in conformity withaccounting principles generally accepted in the United States of America. Basis for Opinion These financial statements are the responsibility of the Plan’s management. Our responsibility is to express an opinion onthe Plan’s financial statements based on our audits. We are a public accounting firm registered with the Public CompanyAccounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Plan inaccordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and ExchangeCommission and the PCAOB. We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan andperformthe audits to obtain reasonable assurance about whether the financial statements are free of materialmisstatement, whether due to error or fraud. The Plan is not required to have, nor were we engaged to perform, an auditof its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internalcontrol over financial reporting, but not for the purpose of expressing an opinion on the effectiveness of the Plan’s internalcontrol over financial reporting. Accordingly, we express no such opinion. 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 includedexamining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits alsoincluded evaluating the accounting principles used and significant estimates made by management, as well as evaluatingthe overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion. Supplemental Information The supplemental information in the accompanying schedule of assets (held at end of year) as of December 31, 2025, hasbeen subjected to audit procedures performed in conjunction with the audit of the Plan’s financial statements. Thesupplemental information is the responsibility of the Plan’s management. Our audit procedures included determiningwhether the supplemental information reconciles to the financial statements or the underlying accounting and otherrecords, as applicable, and performing procedures to test the completeness and accuracy of the information presented inthesupplemental information.In forming our opinion on the supplemental information,we evaluated whether thesupplemental information, including its form and content, is presented in conformity with the Department of Labor's Rulesand Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. In ouropinion, the supplemental information is fairly stated, in all material respects, in relation to the financial statements as awhole. /s/ LBMC, PC We have served as the Plan’s auditor since 2023.Knoxville, TennesseeJune25, 2026 CLEARWATER PAPER 401(k) PLAN Statements of Net Assets Available for Benefits The accompanying note