X0306 4 2023-02-16 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0000923792 CHURCHILL WINSTON J 500 SE MIZNER BLVD. APT 305A BOCA RATON FL 33432-6083 1 0 0 0 Common Stock 2023-02-16 4 M 0 20000 8.51 A 34394 D Common Stock 2023-02-16 4 S 0 20000 27.29 D 14394 D Director Stock Option (Right-to-Buy) 8.51 2023-02-16 4 M 0 20000 0.00 D 2019-05-01 2028-05-01 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 $27.27 to $27.35.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 1, 2018 and vested in full on May 1, 2019. Mark N. Rogers, Attorney-in-Fact for Winston J. Churchill 2023-02-17