Data from SEC EDGARUpdated 11/5/26, 9:45 AM PT

Form 4

Wilderotter Mary Agnes

Director

Filed: 10/24/25
Trade dates: 10/22/25
Period of report: 10/22/25
10b5-1 box: Not checked
Accession number: 0000909832-25-000122

Table I: shares of stock

Line	Security	Trade date	Shares	Price	Value	Owned after	Ownership	Notes
GrantedLine 1 · code A	Common Stock	10/22/25	286Acquired	$0	— No price on filing	3,204.936	Direct	F1, F2, F3
HoldsLine 2Indirect · By GRAT-1	Common Stock	—	—	—	—	9,752	Indirect: By GRAT-1	F3

Footnotes

F1
Grant of Restricted Stock Units. Vests one-third on October 22, 2026, and one-third annually on October 22 for the following two years.
F2
Not applicable. Grant of Restricted Stock Units.
F3
On July 21, 2025, the reporting person contributed 9,752 shares of Costco common stock to a grantor retained annuity trust (GRAT-1) of which the reporting person is the sole grantor, trustee and annuity beneficiary.

Remarks

Exhibit 24: Power of Attorney provided herewith.