X0508 4 2026-02-24 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001965254 Engel Kevin K. 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 1 1 0 0 President and CEO 0 Common Stock 2026-02-24 4 M 0 910 0 A 15825 D Common Stock 2026-02-24 4 F 0 372 48.53 D 15453 D Common Stock 2026-02-24 4 S 0 12500 48.75 D 2953 D Restricted Stock Units 0 2026-02-24 4 M 0 910 0 D Common Stock 910 0 D The transaction represents shares withheld by Amkor Technology, Inc. (the "Issuer") in connection with the vesting of certain restricted stock units ("RSUs") granted to the Reporting Person on February 24, 2022 (the "Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. 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. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $48.73 to $48.81. The Reporting Person hereby undertakes to provide, upon request, to the staff of the Securities and Exchange Commission, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (2) to this Form 4. Represents shares of the Issuer's common stock underlying time-vested RSUs on the 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 vested in four equal annual installments beginning on the first anniversary of the Grant Date. /s/ Mark N. Rogers, Attorney-in-Fact for Kevin Engel 2026-02-26