$COST · Costco Wholesale Corporation

This Form 4 filing reports a transaction in Costco Wholesale Corporation common stock by Gina Marie Raimondo, a director of the company. On October 22, 2026, she acquired 266 shares of common stock at a price of $0. The transaction was a grant of restricted stock units. Following the transaction, she directly beneficially owned 481 shares of Costco common stock.

The restricted stock units vest in three equal installments. One-third vests on October 22, 2027, and one-third vests on October 22 in each of the following two years. The filing does not report any other acquisitions or dispositions of Costco securities by the reporting person during the period covered.