X0306 4 2021-12-27 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001901981 Susins, LLC C/O SIANA CARR O'CONNOR & LYNAM, 1500 EAST LANCASTER AVENUE PAOLI PA 19301-9713 0 0 0 1 Member of 10% owner group (2) Common Stock 2021-12-27 5 G 0 E 164678 23.45 A 164678 D On December 27, 2021, Susan Y. Kim transferred 164,678 shares of the Issuer's Common Stock to the reporting person without consideration. The reporting person is treated as a corporation for purposes of Section 16 of the Securities Exchange Act of 1934, as amended ("Section 16"). John T. Kim and Liam E. Blaney are the managers of the reporting person. 2. 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/ Richard D. Rosen, as Attorney-in-Fact 2022-01-20