$COST · Costco Wholesale Corporation

This SEC Form 4 filing reports changes in beneficial ownership for Gary Millerchip, an Executive Vice President of Costco Wholesale Corporation. The filing discloses transactions dated October 22, 2026. On that date, Millerchip acquired 6,140 shares of Costco common stock at no cost. This acquisition represents the satisfaction of performance conditions tied to a restricted stock unit grant originally made on October 22, 2025. The company’s Compensation Committee determined that the fiscal 2026 performance conditions for those awards had been met. The earned restricted stock units vest in thirds: one-third on the first anniversary of the grant date and an additional one-third in each of the following two years, subject to continued employment.

The filing also reports three separate disposals of common stock on the same date, totaling 1,630.742 shares. These transactions were tax withholdings by the company in connection with the vesting of previously granted restricted stock units. The shares were withheld at a price of $1,018.21 per share, which was the closing market price of Costco common stock on Nasdaq on October 22, 2026. After these transactions, Millerchip directly beneficially owned 19,974.559 shares of Costco common stock.