COSTCO WHOLESALE CORP /NEW (COST) Insider Transactions

Reported filing row; may be amended. Do not sum filings blindly.

F1 Gift to a charitable donor advised fund.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 Gift to a charitable donor advised fund.

References:

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest one-third on the first anniversary of the grant date and an additional one-third vest over each of the ensuing two years based on continued employment with the Company.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest one-third on the first anniversary of the grant date and an additional one-third vest over each of the ensuing two years based on continued employment with the Company.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest one-third on the first anniversary of the grant date and an additional one-third vest over each of the ensuing two years based on continued employment with the Company.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest one-third on the first anniversary of the grant date and an additional one-third vest over each of the ensuing two years based on continued employment with the Company.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest one-third on the first anniversary of the grant date and an additional one-third vest over each of the ensuing two years based on continued employment with the Company.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest 20% on the first anniversary of the grant date and an additional 20% vest over each of the ensuing four years based on continued employment with the Company. In addition, under the 2019 Incentive Plan, this grant is eligible for accelerated vesting upon the anniversary of the reporting person's 25th, 30th and 35th years of service.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest 20% on the first anniversary of the grant date and an additional 20% vest over each of the ensuing four years based on continued employment with the Company. In addition, under the 2019 Incentive Plan, this grant is eligible for accelerated vesting upon the anniversary of the reporting person's 25th, 30th and 35th years of service.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest 20% on the first anniversary of the grant date and an additional 20% vest over each of the ensuing four years based on continued employment with the Company. In addition, under the 2019 Incentive Plan, this grant is eligible for accelerated vesting upon the anniversary of the reporting person's 25th, 30th and 35th years of service.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest 20% on the first anniversary of the grant date and an additional 20% vest over each of the ensuing four years based on continued employment with the Company. In addition, under the 2019 Incentive Plan, this grant is eligible for accelerated vesting upon the anniversary of the reporting person's 25th, 30th and 35th years of service.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest 20% on the first anniversary of the grant date and an additional 20% vest over each of the ensuing four years based on continued employment with the Company. In addition, under the 2019 Incentive Plan, this grant is eligible for accelerated vesting upon the anniversary of the reporting person's 25th, 30th and 35th years of service.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest 20% on the first anniversary of the grant date and an additional 20% vest over each of the ensuing four years based on continued employment with the Company. In addition, under the 2019 Incentive Plan, this grant is eligible for accelerated vesting upon the anniversary of the reporting person's 25th, 30th and 35th years of service.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant of Restricted Stock Units. Vests one-third on October 22, 2027, and one-third on October 22 for the following two years.

F2 Not applicable. Grant of Restricted Stock Units.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant of Restricted Stock Units. Vests one-third on October 22, 2027, and one-third on October 22 for the following two years.

F2 Not applicable. Grant of Restricted Stock Units.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant of Restricted Stock Units. Vests one-third on October 22, 2027, and one-third on October 22 for the following two years.

F2 Not applicable. Grant of Restricted Stock Units.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant of Restricted Stock Units. Vests one-third on October 22, 2027, and one-third on October 22 for the following two years.

F2 Not applicable. Grant of Restricted Stock Units.

F3 On July 21, 2026, 5,056 shares of Costco common stock were distributed to the reporting person in payment of an annuity from a grantor retained annuity trust (GRAT-1) of which she is the sole grantor, trustee and annuity beneficiary.

References: F1, F2, F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest 20% on the first anniversary of the grant date and an additional 20% vest over each of the ensuing four years based on continued employment with the Company.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest 20% on the first anniversary of the grant date and an additional 20% vest over each of the ensuing four years based on continued employment with the Company.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 Grant was initially made on October 22, 2025, subject to performance conditions concerning fiscal 2026, which have been deemed satisfied by the Compensation Committee of the Board of Directors. The earned awards vest 20% on the first anniversary of the grant date and an additional 20% vest over each of the ensuing four years based on continued employment with the Company.

F2 Not applicable. Grant of Restricted Stock Units.

F3 This transaction is a withholding by the Company for taxes in connection with the vesting of previously granted restricted stock units. The price represents the closing market price of Costco common stock on Nasdaq on October 22, 2026.

References: F3