X0508 4 2025-12-12 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001730724 McCourt MaryFrances 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 1 0 0 0 0 Common Stock 2025-12-12 4 M 0 20000 19.39 A 75918 D Common Stock 2025-12-12 4 S 0 20000 46.02 D 55918 D Director Stock Option (Right-to-Buy) 19.39 2025-12-12 4 M 0 20000 0 D 2022-05-17 2031-05-18 Common Stock 20000 0 D The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $45.98 to $46.09. The Reporting Person hereby undertakes to provide, upon request, to the staff of the Securities and Exchange Commission, Amkor Technology, Inc. (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 (1) to this Form 4. This stock option to acquire 20,000 shares of the Issuer's Common Stock was granted on May 18, 2021 and vested in full on May 17, 2022. /s/ Mark N. Rogers, Attorney-in-Fact for MaryFrances McCourt 2025-12-16