X0306 4 2023-02-22 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001201997 ROGERS MARK N 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 0 1 0 0 EVP & General Counsel Common Stock 2023-02-22 4 A 0 35686 0.00 A 40084 D Common Stock 2023-02-22 4 F 0 15343 25.46 D 24741 D Common Stock 2023-02-24 4 M 0 1881 0.00 A 26622 D Common Stock 2023-02-24 4 F 0 807 25.27 D 25815 D Restricted Stock Units 0.00 2023-02-24 4 M 0 1881 0.00 D Common Stock 1881 5642 D This Form 4 reports the vesting on February 22, 2023 of 35,686 shares of common stock of Amkor Technology, Inc. (the "Issuer") underlying performance-vested restricted stock units ("PSUs") granted to the Reporting Person on February 11, 2021 pursuant to the Issuer's Second Amended and Restated 2007 Equity Incentive Plan, as amended, and the related award agreement. The PSUs vested based on the attainment of a basic cumulative earnings per share performance goal over a two-year performance period beginning January 1, 2021 and ending on December 31, 2022. The transaction represents shares of the Issuer's common stock withheld by the Issuer in connection with the vesting of PSUs to satisfy the Reporting Person's tax withholding obligations. The Issuer will pay these taxes on behalf of the Reporting Person. On February 24, 2022 (the "RSU Grant Date"), the Reporting Person was granted 7,523 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's common stock on a one-to-one basis and vest in four equal annual installments beginning on the first anniversary of the RSU Grant Date. The transaction represents shares withheld by the Issuer in connection with the vesting of certain RSUs granted to the Reporting Person on the RSU Grant Date. These shares were withheld to satisfy the Reporting Person's tax withholding obligations. The Issuer will pay these taxes on behalf of the Reporting Person. Mark N. Rogers 2023-02-24