X0508 4 2026-02-16 0 0001047127 AMKOR TECHNOLOGY, INC. AMKR 0001201997 ROGERS MARK N 2045 EAST INNOVATION CIRCLE TEMPE AZ 85284 0 1 0 0 EVP & General Counsel 1 Common Stock 2026-02-16 4 M 0 1856 0 A 25718 D Common Stock 2026-02-16 4 F 0 796 47.48 D 24922 D Common Stock 2026-02-17 4 M 0 5000 7.40 A 29922 D Common Stock 2026-02-17 4 S 0 5000 46.92 D 24922 D Restricted Stock Units 0 2026-02-16 4 M 0 1856 0 D Common Stock 1856 1855 D Employee Stock Option (Right-to-Buy) 7.40 2026-02-17 4 M 0 5000 0 D 2020-06-10 2029-06-10 Common Stock 5000 100000 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 16, 2023 (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. The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 1, 2025. On the Grant Date, the Reporting Person was granted 7,423 RSUs which vest in four equal annual installments beginning on the first anniversary of the Grant Date. This stock option (the "Option") to acquire 200,000 shares of the Issuer's common stock (the "Option Shares") was granted on June 10, 2019 (the "Option Grant Date") and vested over four years as follows: (i) with respect to 25% of the Option Shares, on the first anniversary of the Option Grant Date; and (ii) with respect to the remainder of the Option Shares, in equal quarterly installments thereafter, such that 100% of the Option vested on the fourth anniversary of the Option Grant Date. /s/ Mark N. Rogers 2026-02-18