AMKR

SEC source: 0001628280-26-000446 · wk-form4_1767647892.xml · derivative · entry 3

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 17,384

Underlying: Common Stock · 8,692 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

SEC source: 0001628280-26-000446 · wk-form4_1767647892.xml · nonDerivative · entry 2

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 97,038

F1 · kind: 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.

SEC source: 0001628280-26-000446 · wk-form4_1767647892.xml · nonDerivative · entry 1

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 100,763

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001628280-26-000440 · wk-form4_1767647798.xml · derivative · entry 2

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 17,384

Underlying: Common Stock · 8,692 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: On February 20, 2025, the Reporting Person was granted 43,459 restricted stock units 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.

F1 · derivative.expiration_date: On February 20, 2025, the Reporting Person was granted 43,459 restricted stock units 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.

SEC source: 0001628280-26-000440 · wk-form4_1767647798.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 345,391

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001158839-25-000017 · wk-form4_1767130813.xml · nonDerivative · entry 1

KIM JAMES J · CIK 0001158839 · 10% owner · Member of 10% owner group (4)

10b5-1 filing: No plan indicated

Ownership: Indirect · Susan Y. Kim 2023 Family Distribution Trust

Disclosed balance after: 725,000

F1 · shares: On December 26, 2025, the 2023 Grantor Retained Annuity Trust dated 9/15/2023 distributed 725,000 shares of common stock of Amkor, Inc. (the "Issuer") to the Susan Y. Kim 2023 Family Distribution Trust. Susan Y. Kim is the trustee of the 2023 Grantor Retained Annuity Trust Dated 9/15/2023. The Reporting Person and John T. Kim are co-trustees of the Susan Y. Kim 2023 Family Distribution Trust.

F2 · ownership.direct: The Reporting Person is (i) a trustee of trusts for the benefit of his immediate family members which own 9,786,032 shares of the Issuer's Common Stock (ii) a trustee of a trust which is a controlling member of a limited liability company being treated as a corporation for purposes of Section 16, which limited liability company holds 164,678 shares of the Issuer's Common stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares.

F3 · ownership.direct: 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 ("Section 16"), or for any other purpose.

SEC source: 0001994714-25-000007 · wk-form4_1767130807.xml · nonDerivative · entry 1

2023 Grantor Retained Annuity Trust of Susan Y. Kim Dated 9/15/2023 · CIK 0001994714 · Member of 10% owner group (2)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F1 · shares: On December 26, 2025, the Reporting Person distributed 725,000 shares of common stock of Amkor, Inc. (the "Issuer") to the Susan Y. Kim 2023 Family Distribution Trust. John T. Kim and James J. Kim are co-trustees of the Susan Y. Kim 2023 Family Distribution Trust.

SEC source: 0001158926-25-000014 · wk-form4_1767130800.xml · nonDerivative · entry 1

KIM JOHN T · CIK 0001158926 · 10% owner · Member of 10% owner group (6)

10b5-1 filing: No plan indicated

Ownership: Indirect · By trusts (other than GRAT & Rev. Trust)

Disclosed balance after: 9,846,944

F1 · shares: On December 26, 2025, the 2023 Grantor Retained Annuity Trust dated 9/15/2023 distributed 725,000 shares of common stock of Amkor, Inc. (the "Issuer") to the Susan Y. Kim 2023 Family Distribution Trust. Susan Y. Kim is the trustee of the 2023 Grantor Retained Annuity Trust Dated 9/15/2023. The Reporting Person and James J. Kim are co-trustees of the Susan Y. Kim 2023 Family Distribution Trust.

F2 · ownership.direct: The Reporting Person is (i) a trustee of family trusts for the benefit of his immediate family members (other than Grantor Retained Annuity Trusts ("GRATS") which own 9,846,944 shares of the Issuer's Common Stock, (ii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 1,253,250 shares of the Issuer's Common Stock, (iii) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock (iv) a manager of a limited liability company being treated as a corporation for purposes of Section 16 which owns 16,710,668 shares of the Issuer's Common Stock

F3 · ownership.direct: (continued from Footnote 2) (v) a general partner of a limited partnership which owns 39,594,980 shares of the Issuer's Common Stock and (vi) as referenced in Footnote 4, a member of Sujoda Management, LLC, which indirectly owns 3,789,479 shares of the Issuer's Common Stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares.

F4 · ownership.direct: 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 ("Section 16"), or for any other purpose.

SEC source: 0001158922-25-000021 · wk-form4_1767130790.xml · nonDerivative · entry 1

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (6)

10b5-1 filing: No plan indicated

Ownership: Indirect · By own GRATs

Disclosed balance after: 1,124,000

F1 · shares: On December 26, 2025, the 2023 Grantor Retained Annuity Trust dated 9/15/2023 distributed 725,000 shares of common stock of Amkor, Inc. (the "Issuer") to the Susan Y. Kim 2023 Family Distribution Trust. The Reporting Person is the trustee of the 2023 Grantor Retained Annuity Trust Dated 9/15/2023. John T. Kim and James J. Kim are co-trustees of the Susan Y. Kim 2023 Family Distribution Trust.

F2 · ownership.direct: The Reporting Person is (i) a trustee of trusts for the benefit of her immediate family members (other than grantor retained annuity trusts ("GRATs")) which own 3,713,610 shares of the Common Stock of the Issuer); (ii) a trustee of GRATs for the benefit of members of her immediate family which own 7,912,594 shares of the Issuer's Common Stock; (iii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 1,124,000 shares of the Issuer's Common Stock; (iv) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock

F3 · ownership.direct: (Continued from Footnote 2) (v) a manager of a limited liability company being treated as a corporation for purposes of Section 16 which owns 16,710,668 shares of the Issuer's Common Stock , and (vi) a member of Sujoda Management, LLC, which indirectly owns 3,789,479 shares of the Issuer's Common Stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares.

F4 · ownership.direct: 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 ("Section 16"), or for any other purpose.

SEC source: 0001158840-25-000017 · wk-form4_1767130773.xml · nonDerivative · entry 1

KIM AGNES C · CIK 0001158840 · Member of 10% owner group (3)

10b5-1 filing: No plan indicated

Ownership: Indirect · By Spouse

Disclosed balance after: 10,737,355

F1 · shares: On December 26, 2025, the 2023 Grantor Retained Annuity Trust of Susan Y. Kim Dated 9/15/2023 distributed 725,000 shares of common stock of Amkor, Inc. (the "Issuer") to the Susan Y. Kim 2023 Family Distribution Trust. The spouse of the Reporting Person, James J. Kim, is a co-trustee of the Susan Y. Kim 2023 Family Distribution Trust.

F2 · balance_after: 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 ("Section 16"), or for any other purpose.

SEC source: 0001158922-25-000019 · wk-form4_1766534494.xml · derivative · entry 11

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (8)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,874.901

Underlying: Common Stock · 20.0093 shares

Expires not disclosed

F7 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F7 · derivative.exercise_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F7 · derivative.expiration_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058870 · wk-form4_1767014854.xml · derivative · entry 1

CHURCHILL WINSTON J · CIK 0000923792 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,874.901

Underlying: Common Stock · 20.0093 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.exercise_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.expiration_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058875 · wk-form4_1767015076.xml · derivative · entry 3

ALEXANDER DOUGLAS A · CIK 0001195858 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,874.901

Underlying: Common Stock · 20.0093 shares

Expires not disclosed

F3 · derivative.exercise_price: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F3 · deemedExecutionDate: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F3 · derivative.exercise_date: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F3 · derivative.expiration_date: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058875 · wk-form4_1767015076.xml · derivative · entry 2

ALEXANDER DOUGLAS A · CIK 0001195858 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,880.0635

Underlying: Common Stock · 17.3294 shares

Expires not disclosed

F2 · derivative.exercise_price: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.exercise_date: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.expiration_date: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058875 · wk-form4_1767015076.xml · derivative · entry 1

ALEXANDER DOUGLAS A · CIK 0001195858 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,222.2839

Underlying: Common Stock · 17.7956 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 17, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.exercise_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 17, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.expiration_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 17, 2022. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058873 · wk-form4_1767014931.xml · derivative · entry 2

Carolin Roger Anthony · CIK 0001351909 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,874.901

Underlying: Common Stock · 20.0093 shares

Expires not disclosed

F2 · derivative.exercise_price: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.exercise_date: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.expiration_date: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058873 · wk-form4_1767014931.xml · derivative · entry 1

Carolin Roger Anthony · CIK 0001351909 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,880.0635

Underlying: Common Stock · 17.3294 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.exercise_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.expiration_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058868 · wk-form4_1767014781.xml · derivative · entry 1

Liao Daniel JL · CIK 0001775769 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,874.901

Underlying: Common Stock · 20.0093 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.exercise_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.expiration_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058866 · wk-form4_1767014690.xml · derivative · entry 2

McCourt MaryFrances · CIK 0001730724 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,874.901

Underlying: Common Stock · 20.0093 shares

Expires not disclosed

F2 · derivative.exercise_price: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.exercise_date: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.expiration_date: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058866 · wk-form4_1767014690.xml · derivative · entry 1

McCourt MaryFrances · CIK 0001730724 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,880.0635

Underlying: Common Stock · 17.3294 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.exercise_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.expiration_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058864 · wk-form4_1767014624.xml · derivative · entry 2

Morse Robert Randolph · CIK 0001569086 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,874.901

Underlying: Common Stock · 20.0093 shares

Expires not disclosed

F2 · derivative.exercise_price: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.exercise_date: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F2 · derivative.expiration_date: Represents DEUs accrued upon the payment of a dividend on December 23, 2025 with respect to RSUs of the Issuer granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058864 · wk-form4_1767014624.xml · derivative · entry 1

Morse Robert Randolph · CIK 0001569086 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,880.0635

Underlying: Common Stock · 17.3294 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.exercise_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.expiration_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 16, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058862 · wk-form4_1767014545.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,874.901

Underlying: Common Stock · 20.0093 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.exercise_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.expiration_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001628280-25-058859 · wk-form4_1767014407.xml · derivative · entry 1

WATSON DAVID N · CIK 0001276908 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,874.901

Underlying: Common Stock · 20.0093 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.exercise_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · derivative.expiration_date: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on December 23, 2025 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") granted to the Reporting Person on May 15, 2025. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

SEC source: 0001158922-25-000019 · wk-form4_1766534494.xml · nonDerivative · entry 3

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (8)

10b5-1 filing: No plan indicated

Ownership: Indirect · 2025 Grantor Retained Annuity Trust No. 1 of Agnes C. Kim

Disclosed balance after: 2,538,000

F2 · balance_after: The Reporting Person is (i) a trustee of trusts for the benefit of her immediate family members (other than grantor retained annuity trusts ("GRATs")) which own 3,713,610 shares of the Common Stock of the Issuer); (ii) a trustee of GRATs for the benefit of members of her immediate family which own 7,912,594 shares of the Issuer's Common Stock; (iii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 1,849,000 shares of the Issuer's Common Stock; (iv) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock

F3 · balance_after: (Continued from Footnote 2) (v) a manager of a limited liability company being treated as a corporation for purposes of Section 16 which owns 16,710,668 shares of the Issuer's Common Stock , and (vi) a member of Sujoda Management, LLC, which indirectly owns 3,789,479 shares of the Issuer's Common Stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares.

F4 · balance_after: 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 ("Section 16"), or for any other purpose.

F5 · balance_after: On December 19, 2025, Agnes C. Kim made a distribution of 2,538,000 shares of common stock of the Issuer to the 2025 Grantor Retained Annuity Trust No. 1 of Agnes C. Kim. The Reporting Person is the sole trustee of the 2025 Grantor Retained Annuity Trust No. 1 of Agnes C. Kim.

SEC source: 0001158922-25-000019 · wk-form4_1766534494.xml · nonDerivative · entry 2

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (8)

10b5-1 filing: No plan indicated

Ownership: Indirect · 2025 Grantor Retained Annuity Trust No. 1 of James J. Kim

Disclosed balance after: 3,244,594

F1 · balance_after: On December 19, 2025, James J. Kim made a distribution of 3,244,594 shares of common stock of the Amkor Technology, Inc. (the "Issuer") to the 2025 Grantor Retained Annuity Trust No. 1 of James J. Kim. The Reporting Person is the sole trustee of the 2025 Grantor Retained Annuity Trust No.1 of James J. Kim.

F2 · balance_after: The Reporting Person is (i) a trustee of trusts for the benefit of her immediate family members (other than grantor retained annuity trusts ("GRATs")) which own 3,713,610 shares of the Common Stock of the Issuer); (ii) a trustee of GRATs for the benefit of members of her immediate family which own 7,912,594 shares of the Issuer's Common Stock; (iii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 1,849,000 shares of the Issuer's Common Stock; (iv) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock

F3 · balance_after: (Continued from Footnote 2) (v) a manager of a limited liability company being treated as a corporation for purposes of Section 16 which owns 16,710,668 shares of the Issuer's Common Stock , and (vi) a member of Sujoda Management, LLC, which indirectly owns 3,789,479 shares of the Issuer's Common Stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares.

F4 · balance_after: 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 ("Section 16"), or for any other purpose.

SEC source: 0001158839-25-000015 · wk-form4_1766534487.xml · nonDerivative · entry 2

KIM JAMES J · CIK 0001158839 · 10% owner · Member of 10% owner group (6)

10b5-1 filing: No plan indicated

Ownership: Indirect · By Spouse

Disclosed balance after: 0

F3 · balance_after: On December 19, 2025, the spouse of the Reporting Person, Agnes C. Kim, made a distribution of 2,538,000 shares of common stock of the Issuer to the 2025 Grantor Retained Annuity Trust No. 1 of Agnes C. Kim. Susan Y. Kim is the sole trustee of the 2025 Grantor Retained Annuity Trust No. 1 of Agnes C. Kim.

SEC source: 0001158839-25-000015 · wk-form4_1766534487.xml · nonDerivative · entry 1

KIM JAMES J · CIK 0001158839 · 10% owner · Member of 10% owner group (6)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 61,645

F1 · shares: On November 24, 2025, the Reporting Person reported that the 2024 Grantor Retained Annuity Trust of John J. Kim 8/5/2024 distributed 965,000 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the James J. Kim Revocable Trust dtd 08/30/2018. These shares were inadvertently reported as being held indirectly by the James J. Kim 2018-1 Qualified Annuity Trust U/A on a Form 4 filed by the Reporting Person on November 24, 2025. These shares were direct holdings of the Reporting Person, as the Reporting Person is the settlor, sole trustee, and sole beneficiary of such trust.

F2 · balance_after: On December 19, 2025, the Reporting Person made a distribution of 3,244,594 shares of common stock of the Issuer to the 2025 Grantor Retained Annuity Trust No. 1 of James J. Kim. Susan Y. Kim is the sole trustee of the 2025 Grantor Retained Annuity Trust No.1 of James J. Kim.

SEC source: 0001158840-25-000015 · wk-form4_1766534478.xml · nonDerivative · entry 2

KIM AGNES C · CIK 0001158840 · Member of 10% owner group (4)

10b5-1 filing: No plan indicated

Ownership: Indirect · By Spouse

Disclosed balance after: 10,012,355

F3 · shares: On December 19, 2025, the spouse of the Reporting Person, James J. Kim, made a distribution of 3,244,594 shares of common stock of the Issuer to the 2025 Grantor Retained Annuity Trust No. 1 of James J. Kim. Susan Y. Kim is the sole trustee of the 2025 Grantor Retained Annuity Trust No.1 of James J. Kim.

SEC source: 0001158840-25-000015 · wk-form4_1766534478.xml · nonDerivative · entry 1

KIM AGNES C · CIK 0001158840 · Member of 10% owner group (4)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F1 · shares: On November 24, 2025, the Reporting Person reported that the 2024 Grantor Retained Annuity Trust of Agnes C. Kim 8/5/2024 distributed 705,000 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Agnes C. Kim Revocable Trust dtd 08/30/2018. These shares were inadvertently reported as being held indirectly by the Agnes C. Kim Revocable Trust dtd 08/30/2018 on a Form 4 filed by the Reporting Person on November 24, 2025. These shares were direct holdings of the Reporting Person, as the Reporting Person is the settlor, sole trustee, and sole beneficiary of such trust.

F2 · shares: On December 19, 2025, the Reporting Person made a distribution of 2,538,000 shares of common stock of the Issuer to the 2025 Grantor Retained Annuity Trust No. 1 of Agnes C. Kim. Susan Y. Kim is the sole trustee of the 2025 Grantor Retained Annuity Trust No. 1 of Agnes C. Kim.

SEC source: 0001628280-25-057626 · wk-form4_1766005596.xml · derivative · entry 3

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 110,000

Underlying: Common Stock · 20,000 shares

Expires 2029-06-10

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_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.

SEC source: 0001628280-25-057626 · wk-form4_1766005596.xml · nonDerivative · entry 2

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 23,862

F1 · kind: 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.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $42.15 to $43.65. The Reporting Person hereby undertakes to provide, upon request, to the staff of the Securities and Exchange Commission, Amkor Technology, Inc. (the "Issuer"), or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (2) to this Form 4.

SEC source: 0001628280-25-057626 · wk-form4_1766005596.xml · nonDerivative · entry 1

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 43,862

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001628280-25-057639 · wk-form4_1766005784.xml · derivative · entry 3

CHURCHILL WINSTON J · CIK 0000923792 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 15,000

Underlying: Common Stock · 5,000 shares

Expires 2031-05-18

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: This stock option to acquire 20,000 shares of Common Stock of Amkor Technology, Inc. was granted on May 18, 2021 and vested in full on May 17, 2022.

SEC source: 0001628280-25-057639 · wk-form4_1766005784.xml · nonDerivative · entry 2

CHURCHILL WINSTON J · CIK 0000923792 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 25,888

SEC source: 0001628280-25-057639 · wk-form4_1766005784.xml · nonDerivative · entry 1

CHURCHILL WINSTON J · CIK 0000923792 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,888

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001628280-25-057633 · wk-form4_1766005690.xml · nonDerivative · entry 1

Rutten Guillaume Marie Jean · CIK 0001596796 · Director · President and CEO

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 336,699

F1 · kind: The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 06, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $44.37 to $45.18. The Reporting Person hereby undertakes to provide, upon request, to the staff of the Securities and Exchange Commission, Amkor Technology, Inc. (the "Issuer"), or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (2) to this Form 4.

SEC source: 0001628280-25-057398 · wk-form4_1765920410.xml · derivative · entry 3

McCourt MaryFrances · CIK 0001730724 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 20,000 shares

Expires 2031-05-18

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_date: This stock option to acquire 20,000 shares of the Issuer's Common Stock was granted on May 18, 2021 and vested in full on May 17, 2022.

SEC source: 0001628280-25-057398 · wk-form4_1765920410.xml · nonDerivative · entry 2

McCourt MaryFrances · CIK 0001730724 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 55,918

F1 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $45.98 to $46.09. The Reporting Person hereby undertakes to provide, upon request, to the staff of the Securities and Exchange Commission, Amkor Technology, Inc. (the "Issuer"), or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (1) to this Form 4.

SEC source: 0001628280-25-057398 · wk-form4_1765920410.xml · nonDerivative · entry 1

McCourt MaryFrances · CIK 0001730724 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 75,918

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001628280-25-057395 · wk-form4_1765920340.xml · nonDerivative · entry 1

Engel Kevin · CIK 0001965254 · Executive Vice President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 349

F1 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $45.92 to $46.52. The Reporting Person hereby undertakes to provide, upon request, to the staff of the Securities and Exchange Commission, Amkor Technology, Inc. (the "Issuer"), or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (1) to this Form 4.

F2 · balance_after: On February 21, 2025, the Reporting Person filed a Form 4 which inadvertently overreported the number of shares of common stock of the Issuer ("Shares") withheld by the Issuer in connection with the vesting of performance-vested restricted stock units to satisfy the Reporting Person's tax withholding obligations by 28 Shares. The amount of securities beneficially owned following the transaction reported in this Form 4 reflects a correction to the holdings of the Reporting Person previously reported on Form 4 since February 21, 2025, which understated holdings by 28 Shares.

SEC source: 0001628280-25-057392 · wk-form4_1765920233.xml · nonDerivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 123,806

F1 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $45.91 to $46.83. The Reporting Person hereby undertakes to provide, upon request, to the staff of the Securities and Exchange Commission, Amkor Technology, Inc. (the "Issuer"), or any security holder of the Issuer, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (1) to this Form 4.

SEC source: 0001158922-25-000017 · wk-form4_1765234344.xml · nonDerivative · entry 2

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (6)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,090,494

F1 · balance_after: On December 4, 2025, the Susan Y. Kim 2023 Grantor Retained Annuity Trust dated 9/15/2023 distributed 758,000 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Reporting Person as a gift. Because the Reporting Person is the annuitant and sole trustee of the trust, such distribution was a mere change in the form of ownership from indirect to direct and is being voluntarily reported by the Reporting Person on this Form 4.

SEC source: 0001158922-25-000017 · wk-form4_1765234344.xml · nonDerivative · entry 1

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (6)

10b5-1 filing: No plan indicated

Ownership: Indirect · By own GRATs

Disclosed balance after: 1,849,000

F1 · balance_after: On December 4, 2025, the Susan Y. Kim 2023 Grantor Retained Annuity Trust dated 9/15/2023 distributed 758,000 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Reporting Person as a gift. Because the Reporting Person is the annuitant and sole trustee of the trust, such distribution was a mere change in the form of ownership from indirect to direct and is being voluntarily reported by the Reporting Person on this Form 4.

F2 · ownership.direct: The Reporting Person is (i) a trustee of trusts for the benefit of her immediate family members (other than grantor retained annuity trusts ("GRATs")) which own 3,713,610 shares of the Common Stock of the Issuer); (ii) a trustee of GRATs for the benefit of members of her immediate family which own 3,800,000 shares of the Issuer's Common Stock; (iii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 1,849,000 shares of the Issuer's Common Stock; (iv) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock

F3 · ownership.direct: (Continued from Footnote 2) (v) a manager of a limited liability company being treated as a corporation for purposes of Section 16 which owns 16,710,668 shares of the Issuer's Common Stock and (vi) as referenced in Footnote 9, below, a member of Sujoda Management, LLC, which indirectly owns 3,789,479 shares of the Issuer's Common Stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares.

F4 · ownership.direct: 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 ("Section 16"), or for any other purpose.

SEC source: 0001994714-25-000005 · wk-form4_1765234269.xml · nonDerivative · entry 1

2023 Grantor Retained Annuity Trust of Susan Y. Kim Dated 9/15/2023 · CIK 0001994714 · Member of 10% owner group (2)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 725,000

F1 · balance_after: On December 4, 2025, the Reporting Person distributed 758,000 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to Susan Y. Kim as a gift.

SEC source: 0001158839-25-000013 · wk-form4_1764035900.xml · nonDerivative · entry 1

KIM JAMES J · CIK 0001158839 · 10% owner · Member of 10% owner group (4)

10b5-1 filing: No plan indicated

Ownership: Indirect · By trusts (excluding GRATs)

Disclosed balance after: 965,000

F1 · shares: On November 20, 2025, the 2024 Grantor Retained Annuity Trust of James J. Kim 8/5/2024 distributed 965,000 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the James J. Kim 2018-1 Qualified Annuity Trust U/A dated 8/30/18. The Reporting Person and Susan Y. Kim are co-trustees of the trust.

SEC source: 0001158922-25-000015 · wk-form4_1764035907.xml · nonDerivative · entry 5

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (10)

10b5-1 filing: No plan indicated

Ownership: Indirect · By trusts (excl. GRATs)

Disclosed balance after: 3,713,610

F6 · shares: On November 20, 2025, the 2024 Grantor Retained Annuity Trust of Agnes C. Kim 8/5/2024 distributed 705,000 shares of the Common Stock of Amkor Technology, Inc (the "Issuer") to the the Agnes C. Kim Revocable Trust, of which Agnes C. Kim is the sole settlor, sole beneficiary, and sole trustee. Susan Y. Kim is the sole trustee of the 2024 Grantor Retained Annuity Trust of Agnes C. Kim 8/5/2024.

F2 · ownership.direct: The Reporting Person is (i) a trustee of trusts for the benefit of her immediate family members (other than grantor retained annuity trusts ("GRATs")) which own 3,453,610 shares of the Common Stock of the Issuer); (ii) a trustee of GRATs for the benefit of members of her immediate family which own 3,800,000 shares of the Issuer's Common Stock; (iii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 2,607,00 shares of the Issuer's Common Stock; (iv) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock

F3 · ownership.direct: (Continued from Footnote 2) (v) a manager of a limited liability company being treated as a corporation for purposes of Section 16 which owns 16,710,668 shares of the Issuer's Common Stock and (vi) as referenced in Footnote 9, below, a member of Sujoda Management, LLC, which indirectly owns 3,789,479 shares of the Issuer's Common Stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares.

F4 · ownership.direct: 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 ("Section 16"), or for any other purpose.

SEC source: 0001158922-25-000015 · wk-form4_1764035907.xml · nonDerivative · entry 4

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (10)

10b5-1 filing: No plan indicated

Ownership: Indirect · By trusts (excl. GRATs)

Disclosed balance after: 4,418,610

F5 · shares: On November 20, 2025, the 2024 Grantor Retained Annuity Trust of James J. Kim 8/5/2024 distributed 965,000 shares of the Common Stock of the Issuer to the James J. Kim 2018-1 Qualified Annuity Trust U/A dated 8/30/18. The Reporting Person is the trustee of the 2024 Grantor Retained Annuity Trust of James J. Kim 8/5/2024. The Reporting Person and James J. Kim are co-trustees of the James J. Kim 2018-1 Qualified Annuity Trust U/A dated 8/30/18.

F2 · ownership.direct: The Reporting Person is (i) a trustee of trusts for the benefit of her immediate family members (other than grantor retained annuity trusts ("GRATs")) which own 3,453,610 shares of the Common Stock of the Issuer); (ii) a trustee of GRATs for the benefit of members of her immediate family which own 3,800,000 shares of the Issuer's Common Stock; (iii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 2,607,00 shares of the Issuer's Common Stock; (iv) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock

F3 · ownership.direct: (Continued from Footnote 2) (v) a manager of a limited liability company being treated as a corporation for purposes of Section 16 which owns 16,710,668 shares of the Issuer's Common Stock and (vi) as referenced in Footnote 9, below, a member of Sujoda Management, LLC, which indirectly owns 3,789,479 shares of the Issuer's Common Stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares.

F4 · ownership.direct: 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 ("Section 16"), or for any other purpose.

SEC source: 0001158922-25-000015 · wk-form4_1764035907.xml · nonDerivative · entry 3

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (10)

10b5-1 filing: No plan indicated

Ownership: Indirect · By trusts (excl. GRATs)

Disclosed balance after: 3,453,610

F5 · shares: On November 20, 2025, the 2024 Grantor Retained Annuity Trust of James J. Kim 8/5/2024 distributed 965,000 shares of the Common Stock of the Issuer to the James J. Kim 2018-1 Qualified Annuity Trust U/A dated 8/30/18. The Reporting Person is the trustee of the 2024 Grantor Retained Annuity Trust of James J. Kim 8/5/2024. The Reporting Person and James J. Kim are co-trustees of the James J. Kim 2018-1 Qualified Annuity Trust U/A dated 8/30/18.

F2 · ownership.direct: The Reporting Person is (i) a trustee of trusts for the benefit of her immediate family members (other than grantor retained annuity trusts ("GRATs")) which own 3,453,610 shares of the Common Stock of the Issuer); (ii) a trustee of GRATs for the benefit of members of her immediate family which own 3,800,000 shares of the Issuer's Common Stock; (iii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 2,607,00 shares of the Issuer's Common Stock; (iv) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock

F3 · ownership.direct: (Continued from Footnote 2) (v) a manager of a limited liability company being treated as a corporation for purposes of Section 16 which owns 16,710,668 shares of the Issuer's Common Stock and (vi) as referenced in Footnote 9, below, a member of Sujoda Management, LLC, which indirectly owns 3,789,479 shares of the Issuer's Common Stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares.

F4 · ownership.direct: 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 ("Section 16"), or for any other purpose.

SEC source: 0001158922-25-000015 · wk-form4_1764035907.xml · nonDerivative · entry 2

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (10)

10b5-1 filing: No plan indicated

Ownership: Indirect · By own GRATs

Disclosed balance after: 2,607,000

F1 · shares: On November 20, 2025, the 2024 Grantor Retained Annuity Trust of Susan Y. Kim dtd. 8/5/2024 distributed 876,000 shares of the Common Stock of Amkor Technology, Inc (the "Issuer") to the Reporting Person. The Reporting Person is the sole trustee of the 2024 Grantor Retained Annuity Trust of Susan Y. Kim dtd. 8/5/2024. Because the Reporting Person is the annuitant and sole trustee of the 2024 Grantor Retained Annuity Trust of Susan Y. Kim dtd. 8/5/2024, the distribution was a mere change in the form of ownership from indirect to direct and thus being voluntarily reported by the Reporting Person on this Form 4.

F2 · ownership.direct: The Reporting Person is (i) a trustee of trusts for the benefit of her immediate family members (other than grantor retained annuity trusts ("GRATs")) which own 3,453,610 shares of the Common Stock of the Issuer); (ii) a trustee of GRATs for the benefit of members of her immediate family which own 3,800,000 shares of the Issuer's Common Stock; (iii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 2,607,00 shares of the Issuer's Common Stock; (iv) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock

F3 · ownership.direct: (Continued from Footnote 2) (v) a manager of a limited liability company being treated as a corporation for purposes of Section 16 which owns 16,710,668 shares of the Issuer's Common Stock and (vi) as referenced in Footnote 9, below, a member of Sujoda Management, LLC, which indirectly owns 3,789,479 shares of the Issuer's Common Stock. Pursuant to the Form 4 instructions, the Reporting Person is being treated as having a pecuniary interest in all of such shares.

F4 · ownership.direct: 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 ("Section 16"), or for any other purpose.