X0508 4 2023-09-25 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001195858 ALEXANDER DOUGLAS A 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 1 0 0 0 0 Restricted Stock Units 2023-09-25 4 A 0 29.1626 0.00 A Common Stock 29.1626 8863.3406 D Restricted Stock Units 2023-09-25 4 A 0 28.3988 0.00 A Common Stock 28.3988 8530.5206 D Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on September 25, 2023 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 17, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued. Represents DEUs accrued upon the payment of a dividend on September 25, 2023 with respect to RSUs of the Issuer granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued. Mark N. Rogers, Attorney-in-Fact for Douglas A. Alexander 2023-09-27