X0407 4 2023-06-02 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001965254 Engel Kevin 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 0 1 0 0 Executive Vice President 0 Common Stock 2023-06-02 4 S 0 3570 25.42 D 0 D Employee Stock Option (Right-to-Buy) 2029-02-15 Common Stock 0 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.41 to $25.44. 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. As previously reported in a Form 4 filed by the Reporting Person on February 24, 2023 (the "Original Form 4"), 6,250 shares (the "Option Shares") of the Issuer's common stock underlying an option to acquire 100,000 shares of the Issuer's common stock were exercised and sold on February 23, 2023. Pursuant to the award agreement for the Option Shares, the expiration date for the Option Shares is February 15, 2029. In the Original Form 4, the expiration date for the Option Shares was incorrectly reported. Table II, Column 6 has been adjusted to include the proper expiration date for the Option Shares. Mark N. Rogers, Attorney-in-Fact for Kevin Engel 2023-06-06