COST · Costco Wholesale Corp · Insider Trading

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, employees are eligible for accelerated vesting upon the anniversary of their 25th, 30th and 35th years of service.

Not applicable. Grant of Restricted Stock Units.

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, employees are eligible for accelerated vesting upon the anniversary of their 25th, 30th and 35th years of service.

Not applicable. Grant of Restricted Stock Units.

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, employees are eligible for accelerated vesting upon the anniversary of their 25th, 30th and 35th years of service.

Not applicable. Grant of Restricted Stock Units.

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, employees are eligible for accelerated vesting upon the anniversary of their 25th, 30th and 35th years of service.

Not applicable. Grant of Restricted Stock Units.

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, employees are eligible for accelerated vesting upon the anniversary of their 25th, 30th and 35th years of service.

Not applicable. Grant of Restricted Stock Units.

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, employees are eligible for accelerated vesting upon the anniversary of their 25th, 30th and 35th years of service.

Not applicable. Grant of Restricted Stock Units.

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, employees are eligible for accelerated vesting upon the anniversary of their 25th, 30th and 35th years of service.

Not applicable. Grant of Restricted Stock Units.

Gift to a non-profit foundation.

The price shown is a weighted average price for shares sold in multiple transactions; the sale prices ranged from $957.44 to $957.63 per share. The reporting person will provide the issuer, any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

Reflects a transaction by which the reporting person through an intra-plan transfer disposed of the 642.1252 shares of common stock previously reported as beneficially owned under Costco's 401(k) plan, pursuant to the company's policy prohibiting executive officers from participating in the common stock fund.

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 March 11, 2026.

Gift to a non-profit foundation.

Gift to a charitable donor advised fund.

The price shown is a weighted average price for shares sold in multiple transactions; the sale prices ranged from $986.220 to $986.480 per share. The reporting person will provide the issuer, any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

Grant of Restricted Stock Units. Vests one-third on October 22, 2026, and one-third annually on October 22 for the following two years.

Not applicable. Grant of Restricted Stock Units.

The price shown is a weighted average price for shares sold in multiple transactions; the sale prices ranged from $867.16 to $867.325 per share. The reporting person will provide the issuer, any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

Gift to a charitable donor advised fund.

Gift to a non-profit organization.

On October 23, 2025, the reporting person received a distribution of 4,400.9692 shares of common stock previously beneficially owned through Costco's 401(k) plan. Upon the distribution, a fractional share of .9692 was liquidated and the total amount owned was reduced by such amount.

The price shown is a weighted average price for shares sold in multiple transactions; the sale prices ranged from $934.47 to $934.84 per share. The reporting person will provide the issuer, any security holder of the issuer, or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

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, 2025.

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, 2025.

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, 2025.

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, 2025.

Grant of Restricted Stock Units. Vests one-third on October 22, 2026, and one-third annually on October 22 for the following two years.

Not applicable. Grant of Restricted Stock Units.

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, 2025.

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, 2025.

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, 2025.

Grant of Restricted Stock Units. Vests one-third on October 22, 2026, and one-third annually on October 22 for the following two years.

Not applicable. Grant of Restricted Stock Units.

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, 2025.

Grant of Restricted Stock Units. Vests one-fifth on October 22, 2026, and one-fifth annually on October 22 for the following four years. In addition, under the Stock Incentive Plan, employees are eligible for accelerated vesting upon the anniversary of their 25th, 30th and 35th years of service.

Not applicable. Grant of Restricted Stock Units.

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, 2025.