X0508 4 2023-12-22 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001158839 KIM JAMES J C/O SIANA CARR O'CONNOR & LYNAM 1500 EAST LANCASTER AVENUE PAOLI PA 19301-9713 1 0 1 1 Member of 10% owner group (4) 0 Common Stock 2023-12-22 4 G 0 715000 0.00 A 715000 I By Spouse Common Stock 798902 D Common Stock 1957350 I By John T. Kim G-S Trust dtd. 12/11/12 Common Stock 7828682 I By John T. Kim Family Trust U/A dtd. 12/11/12 Common Stock 1338097 I By self as Trustee of own GRATs Common Stock 164678 I By self as Trustee of Trust U/A dtd. 12/11/12 On December 22, 2023, the Agnes C. Kim 2020-1 Qualified Annuity Trust Under Agreement dated 12/6/2020 (the "ACK Trust") distributed 715,000 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to Agnes C. Kim. Agnes C. Kim is the spouse of the Reporting Person. Susan Y. Kim is the sole trustee of the ACK Trust. 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 of the Securities Exchange Act of 1934, as amended ("Section 16"), or for any other purpose. The Reporting Person is (i) a trustee of grantor retained annuity trusts of which he was the settlor and is the sole annuitant which own 1,338,097 shares of the Issuer's Common Stock, (ii) a trustee of trusts for the benefit of his immediate family members which own 9,786,032 shares of the Issuer's Common Stock and (iii) a trustee of a trust which is a controlling member of a limited liability company being treated as a corporation for purposes of Section 16, which limited liability company holds 164,678 shares of the Issuer's Common stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares. (4) The Reporting Person states that the filing of this Form 4 shall not be deemed an admission that the Reporting Person is the beneficial owner of the reported securities owned by the other members of the group, for the purpose of Section 16, or for any other purpose. /s/ Brian D. Short, Attorney-in-Fact for James J. Kim 2023-12-27