COSTCO WHOLESALE CORP /NEW 4

Executive Vice President Claudine Adamo received a performance-based RSU award converting into Costco common stock, with a portion of shares withheld for taxes, resulting in 10,250.195 shares owned directly.

On September 10, 2026, Executive Vice President Claudine Adamo of Costco Wholesale Corp. had performance-based restricted stock units convert into 4,129 shares of common stock, of which 916.685 shares were withheld at an implied price of approximately $902.38 per share to cover tax obligations, leaving her with direct ownership of 10,250.195 shares after the transaction. The underlying grant was originally awarded on October 22, 2025, contingent on fiscal 2026 performance goals that were later certified as achieved by the Compensation Committee, and the earned units vest in 20% installments annually over five years, with potential acceleration under Costco’s 2019 Incentive Plan for long-tenured employees. This filing reflects routine equity compensation vesting and associated tax withholding rather than an open-market purchase or discretionary sale.

Filing Facts

CIK

909832

Ticker

COST

Form

4

Source Type

sec

Accession

0000909832-26-000068

Alert Tier

7