X0306 4 2021-05-18 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001158922 KIM SUSAN Y C/O SIANA CARR O'CONNOR & LYNAM, 1500 EAST LANCASTER AVENUE, PAOLI PA 19301-9713 1 0 1 1 Exhibit 99.1 Common Stock 2021-05-18 4 A 0 3094 0.00 A 4516475 D Common Stock 32339816 I Held by Self as Trustee Common Stock 25674640 I Held by Self Through Partnerships Director Stock Option (Right to Buy) 19.39 2021-05-18 4 A 0 20000 0.00 A 2031-05-18 Amkor Technology Inc. Common Stock 20000 20000 D These are restricted shares which vest 100% on the earlier of the first anniversary of the grant date, or the date of the first annual meeting of stockholders following the grant date. 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, or for any other purpose. These options vest 100% on the earlier of the first anniversary of the grant date or the date of the first annual meeting of stockholders following the grant date. Mark N. Rogers, Attorney-in-Fact for Susan Y. Kim 2021-05-19