X0508 4 2026-02-18 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001596796 Rutten Guillaume Marie Jean 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 1 0 0 0 0 Common Stock 2026-02-18 4 A 0 10891 0 A 350202 D Common Stock 2026-02-18 4 A 0 30587 0 A 380789 D This Form 4 reports the vesting on February 18, 2026 of 10,891 shares of common stock of Amkor Technology, Inc. (the "Issuer") underlying performance-vested restricted stock units ("PSUs") granted to the Reporting Person on February 20, 2024 pursuant to the Issuer's Equity Incentive Plan, as amended, and the related award agreement. The PSUs vested based on the attainment of a basic earnings per share performance goal over a one-year performance period beginning January 1, 2025 and ending on December 31, 2025. This Form 4 reports the vesting on February 18, 2026 of 30,587 shares of common stock of the Issuer's underlying PSUs granted to the Reporting Person on February 20, 2025 pursuant to the Issuer's Equity Incentive Plan, as amended, and the related award agreement. The PSUs vested based on the attainment of a basic earnings per share performance goal over a one-year performance period beginning January 1, 2025 and ending on December 31, 2025. /s/ Mark N. Rogers, Attorney-in-Fact for Guillaume Marie Jean Rutten 2026-02-20