Shareholder Vote · Company Update

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 15, 2026 COSTCO WHOLESALE CORPORATION (Exact name of registrant as specified in its charter) Washington 0-20355 91-1223280 (State or other jurisdiction of incorporation) (Commission File No.) (I.R.S. Employer Identification No.) 999 Lake Drive Issaquah , WA 98027 (Address of principal executive offices and zip code) Registrant’s telephone number, including area code: 425 - 313-8100 Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock, par value $.005 per share COST NASDAQ Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ Item 5.07.     Submission of Matters to a Vote of Security Holders On January 15, 2026, Costco Wholesale Corporation (the "Company") held its Annual Meeting of Shareholders. There were 443,957,682 shares of common stock entitled to be voted; 352,303,581 shares were voted in person or by proxy. Shareholders voted on the following matters: 1. The election of each of the directors nominated by the Board of Directors to hold office until the 2027 Annual Meeting of Shareholders and until their successors are elected and qualified; 2. The ratification of the selection of KPMG LLP as the Company's independent auditors for fiscal year 2026; 3. The approval, on an advisory basis, of the compensation of the Company's executive officers for fiscal year 2025 as disclosed in the Company's definitive proxy statement on Schedule 14A for the Annual Meeting, filed with the Securities and Exchange Commission on December 4, 2025; and 4. A shareholder proposal regarding greenwashing risk audit. All items except item 4 were approved. The results of the votes are set forth below: Election of Directors Nominees For Against Abstain Broker Non-Votes Susan L. Decker 271,388,023 15,209,023 394,831 65,311,704 Kenneth D. Denman 284,834,609 1,548,385 608,883 65,311,704 Helena B. Foulkes 282,748,943 3,468,233 774,701 65,311,704 Hamilton E. James 272,025,889 14,520,910 445,078 65,311,704 Sally Jewell 282,618,424 3,964,410 409,043 65,311,704 Jeffrey S. Raikes 273,652,014 12,901,665 438,198 65,311,704 Gina M. Raimondo 285,239,485 1,198,976 553,416 65,311,704 John W. Stanton 277,740,958 8,807,979 442,940 65,311,704 Ron M. Vachris 284,866,409 1,694,961 430,507 65,311,704 Maggie Wilderotter 276,414,143 9,947,380 630,354 65,311,704 Ratification of the Selection of Auditors: For Against Abstain 335,155,664 16,539,396 608,521 Advisory Vote on Executive Compensation: For Against Abstain Broker Non-Votes 251,441,227 34,380,984 1,169,666 65,311,704 Shareholder Proposal Regarding Greenwashing Risk Audit: For Against Abstain Broker Non-Votes 4,058,782 279,690,631 3,242,464 65,311,704 Item 8.01.     Other Events The Board of Directors declared a quarterly cash dividend on the Company's common stock of $1.30 per share. The dividend was declared on January 15, 2026, and is payable February 13, 2026, to shareholders of record at the close of business on January 30, 2026. Item 9.01.     Financial Statements and Exhibits (d) Exhibits. 99.1.     Press Release dated January 15 , 202 6 . 104    Cover Page Interactive Data File (embedded within the Inline XBRL document). SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized. COSTCO WHOLESALE CORPORATION Dated: January 21, 2026 By: /s/ John Sullivan John Sullivan Executive Vice President, General Counsel and Corporate Secretary