Susan Y. Kim Form 4 Filing for Amkor Technology - Dividend Equivalent Units Accrual

This Form 4 filing reports that Susan Y. Kim, a director and member of the 10% owner group of Amkor Technology, Inc., accrued 2.5166 dividend equivalent units (DEUs) on June 23, 2026, related to time-vested restricted stock units granted on May 13, 2026. The DEUs represent additional RSUs subject to the same provisions as the original RSUs. The filing also details Kim's extensive beneficial ownership of Amkor common stock through various entities, including direct ownership of 6,120,387 shares and indirect ownership through family trusts, GRATs, and limited partnerships totaling approximately 37.8 million additional shares. Kim disclaims beneficial ownership of securities held by other members of the group except to the extent of her pecuniary interest. The filing was signed by Mark N. Rogers as attorney-in-fact for Susan Y. Kim on June 25, 2026.