X0508 4 2025-12-19 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001158840 KIM AGNES C C/O SIANA CARR O'CONNOR & LYNAM 1500 EAST LANCASTER AVENUE PAOLI PA 19301-9713 0 0 0 1 Member of 10% owner group (4) 0 Common Stock 2025-12-19 4 G 0 2538000 0 D 0 D Common Stock 2025-12-19 4 G 0 3244594 0 D 10012355 I By Spouse On November 24, 2025, the Reporting Person reported that the 2024 Grantor Retained Annuity Trust of Agnes C. Kim 8/5/2024 distributed 705,000 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Agnes C. Kim Revocable Trust dtd 08/30/2018. These shares were inadvertently reported as being held indirectly by the Agnes C. Kim Revocable Trust dtd 08/30/2018 on a Form 4 filed by the Reporting Person on November 24, 2025. These shares were direct holdings of the Reporting Person, as the Reporting Person is the settlor, sole trustee, and sole beneficiary of such trust. On December 19, 2025, the Reporting Person made a distribution of 2,538,000 shares of common stock of the Issuer to the 2025 Grantor Retained Annuity Trust No. 1 of Agnes C. Kim. Susan Y. Kim is the sole trustee of the 2025 Grantor Retained Annuity Trust No. 1 of Agnes C. Kim. On December 19, 2025, the spouse of the Reporting Person, James J. Kim, made a distribution of 3,244,594 shares of common stock of the Issuer to the 2025 Grantor Retained Annuity Trust No. 1 of James J. Kim. Susan Y. Kim is the sole trustee of the 2025 Grantor Retained Annuity Trust No.1 of James J. Kim. (4) The Reporting Person disclaims beneficial ownership of these securities, except to the extent of the Reporting Person's pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities, except to the extent of the Reporting Person's pecuniary interest therein, for purposes of Section 16,or for any other purpose. /s/ Brian D. Short, Attorney-in-Fact for Agnes C. Kim 2025-12-23