X0508 4 2026-02-20 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001596796 Rutten Guillaume Marie Jean 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 1 0 0 0 0 Common Stock 2026-02-20 4 M 0 112941 0 A 493730 D Common Stock 2026-02-20 4 M 0 59388 0 A 553118 D Restricted Stock Units 0 2026-02-20 4 M 0 112941 0 D Common Stock 112941 56470 D Restricted Stock Units 0 2026-02-20 4 M 0 59388 0 D Common Stock 59388 118795 D Represents shares of Amkor Technology, Inc. (the "Issuer") common stock underlying time-vested restricted stock units ("RSUs") granted on February 20, 2024 (the "2024 Grant Date") pursuant to the Issuer's Equity Incentive Plan. The RSUs were awarded for no consideration other than the Reporting Person's service as a service provider of the Issuer and will vest over three years, with 40% of the RSUs vesting on each of the first anniversary and the second anniversary of the 2024 Grant Date, and 20% vesting on the third anniversary of the 2024 Grant Date, such that 100% will be vested on the third anniversary of the 2024 Grant Date. Represents shares of the Issuer's common stock underlying time-vested RSUs granted on February 20, 2025 (the "2025 Grant Date") pursuant to the Issuer's Equity Incentive Plan. The RSUs were awarded for no consideration other than the Reporting Person's service as a service provider of the Issuer and will vest in three equal annual installments beginning on the first anniversary of the 2025 Grant Date and annually thereafter, such that 100% will be vested on the third anniversary of the 2025 Grant Date. /s/ Mark N. Rogers, Attorney-in-Fact for Guillaume Marie Jean Rutten 2026-02-24