X0508 4 2025-12-31 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001965254 Engel Kevin 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 0 1 0 0 Executive Vice President 0 Common Stock 2025-12-31 4 M 0 8692 0 A 9041 D Common Stock 2025-12-31 4 F 0 3725 39.48 D 5316 D Restricted Stock Units 0 2025-12-31 4 M 0 8692 0 D Common Stock 8692 17384 D The transaction represents shares withheld by Amkor Technology, Inc. (the "Issuer") in connection with the vesting of certain restricted stock units ("RSUs") granted to the Reporting Person on February 20, 2025 (the "Grant Date") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the related award agreement. These shares were withheld to satisfy the Reporting Person's tax withholding obligations. The Issuer will pay these taxes on behalf of the Reporting Person. On the Grant Date, the Reporting Person was granted 43,459 RSUs which vest in five equal quarterly installments on each of June 30, 2025, September 30, 2025, December 31, 2025, March 31, 2026, and June 30, 2026, such that 100% will be vested on June 30, 2026. /s/ Mark N. Rogers, Attorney-in-Fact for Kevin Engel 2026-01-05