AMKR

SEC source: 0001209191-23-055582 · doc4.xml · nonDerivative · entry 1

Blaney Liam E · CIK 0001901848 · Member of 10% owner group (4)

10b5-1 filing: No plan indicated

Ownership: Indirect · By Alexandra Investments, LLC

Disclosed balance after: 0

F1 · shares: On November 14, 2023, Alexandra Investments, LLC ("AI LLC") distributed 2,733,333 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to Kim Capital Partners - KCP, LLC. The Reporting Person and Susan Y. Kim are the managers of AI LLC.

SEC source: 0001209191-23-054413 · doc4.xml · nonDerivative · entry 1

ROGERS MARK N · CIK 0001201997 · EVP & General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,815

F1 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $23.83 to $23.86.

SEC source: 0001209191-23-053496 · doc4.xml · derivative · entry 3

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 13,600

Underlying: Common Stock · 2,700 shares

Expires 2029-02-15

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 150,000 shares of the Issuer's common stock (the "Option Shares") was granted on February 15, 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: 0001209191-23-053496 · doc4.xml · nonDerivative · entry 2

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,394

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 February 23, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.41 to $22.61. 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: 0001209191-23-053496 · doc4.xml · nonDerivative · entry 1

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 38,094

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: 0001209191-23-053366 · doc4.xml · nonDerivative · entry 1

Qualified Annuity Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dtd August 29, 2018 · CIK 0001755764 · Member of 10% owner group (2)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F1 · shares: On October 19, 2023, the Reporting Person distributed 1,211,193 shares of the Common Stock of Amkor Technology, Inc. to the Family Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dated 8/29/18. James J. Kim and Susan Y. Kim are co-trustees of the Reporting Person.

SEC source: 0001209191-23-053364 · doc4.xml · nonDerivative · entry 2

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

10b5-1 filing: No plan indicated

Ownership: Indirect · By Susan Y. Kim Family Trust U/A dtd. 8/29/18

Disclosed balance after: 1,211,193

F1 · shares: On October 19, 2023, the Qualified Annuity Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dated 8/29/18 (the "SYK 2018 GRAT") distributed 1,211,193 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Family Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dated 8/29/18 (the "SYK 2018 Family Trust"). The Reporting Person and Susan Y. Kim are co-trustees of the SYK 2018 GRAT and SYK 2018 Family 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.

F3 · balance_after: The Reporting Person is (i) a trustee of grantor retained annuity trusts of which he was the settlor and is the sole annuitant which own 1,867,747 shares of the Issuer's Common Stock, (ii) a trustee of trusts for the benefit of his immediate family members which own 12,955,580 shares of the Issuer's Common Stock, (iii) 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, and (iv) a general partner of a limited partnership which owns 39,594,980 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.

SEC source: 0001209191-23-053364 · doc4.xml · nonDerivative · entry 1

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

10b5-1 filing: No plan indicated

Ownership: Indirect · By Susan Y. Kim 2018-1 GRAT dtd. 8/29/18

Disclosed balance after: 0

F1 · shares: On October 19, 2023, the Qualified Annuity Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dated 8/29/18 (the "SYK 2018 GRAT") distributed 1,211,193 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Family Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dated 8/29/18 (the "SYK 2018 Family Trust"). The Reporting Person and Susan Y. Kim are co-trustees of the SYK 2018 GRAT and SYK 2018 Family Trust.

SEC source: 0001209191-23-052793 · doc4.xml · nonDerivative · entry 1

Qualified Annuity Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dtd August 29, 2018 · CIK 0001755764 · Member of 10% owner group (2)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,211,193

F1 · shares: On October 11, 2023, the Reporting Person distributed 168,750 shares of the Common Stock of Amkor Technology, Inc. to Susan Y. Kim. James J. Kim and Susan Y. Kim are co-trustees of the Reporting Person.

SEC source: 0001209191-23-052792 · doc4.xml · nonDerivative · entry 1

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

10b5-1 filing: No plan indicated

Ownership: Indirect · By Susan Y. Kim 2018-1 GRAT dtd. 8/29/18

Disclosed balance after: 1,211,193

F1 · shares: On October 11, 2023, the Qualified Annuity Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dtd. 8/29/18 distributed 168,750 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to Susan Y. Kim. The Reporting Person and Susan Y. Kim are co-trustees of the 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.

F3 · balance_after: The Reporting Person is (i) a trustee of grantor retained annuity trusts of which he was the settlor and is the sole annuitant which own 1,867,747 shares of the Issuer's Common Stock, (ii) a trustee of trusts for the benefit of his immediate family members which own 12,955,580 shares of the Issuer's Common Stock, (iii) 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, and (iv) a general partner of a limited partnership which owns 39,594,980 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.

SEC source: 0001209191-23-052791 · doc4.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: 54,852,237

F1 · shares: On October 11, 2023, the Qualified Annuity Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dtd. 8/29/18 distributed 168,750 shares of the Common Stock of of Amkor Technology, Inc. to Susan Y. Kim. The Reporting Person's spouse is a trustee of the trust.

F2 · balance_after: James J. Kim is the spouse of the Reporting Person. 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: 0001209191-23-050667 · doc4.xml · derivative · entry 1

CHURCHILL WINSTON J · CIK 0000923792 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,530.5206

Underlying: Common Stock · 28.3988 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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: 0001209191-23-050673 · doc4.xml · derivative · entry 1

WATSON DAVID N · CIK 0001276908 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,530.5206

Underlying: Common Stock · 28.3988 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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: 0001209191-23-050672 · doc4.xml · derivative · entry 1

Tily Gil C. · CIK 0001405591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,530.5206

Underlying: Common Stock · 28.3988 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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: 0001209191-23-050671 · doc4.xml · derivative · entry 1

McCourt MaryFrances · CIK 0001730724 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,530.5206

Underlying: Common Stock · 28.3988 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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: 0001209191-23-050670 · doc4.xml · derivative · entry 1

Morse Robert Randolph · CIK 0001569086 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,530.5206

Underlying: Common Stock · 28.3988 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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: 0001209191-23-050668 · doc4.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: 8,530.5206

Underlying: Common Stock · 28.3988 shares

Expires not disclosed

F7 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of the Issuer upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F7 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of the Issuer upon the Issuer's payment of a dividend on September 25, 2023. 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 with respect to time-vested restricted stock units ("RSUs") of the Issuer upon the Issuer's payment of a dividend on September 25, 2023. 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 with respect to time-vested restricted stock units ("RSUs") of the Issuer upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F7 · derivative.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of the Issuer upon the Issuer's payment of a dividend on September 25, 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: 0001209191-23-050669 · doc4.xml · derivative · entry 1

Liao Daniel JL · CIK 0001775769 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,530.5206

Underlying: Common Stock · 28.3988 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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: 0001209191-23-050666 · doc4.xml · derivative · entry 1

Carolin Roger Anthony · CIK 0001351909 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,530.5206

Underlying: Common Stock · 28.3988 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 2023. Each DEU represents an additional RSU subject to the same provisions as the RSU with respect to which the DEU was accrued.

F1 · shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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 with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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.underlying_shares: Represents dividend equivalent units ("DEUs") accrued with respect to time-vested restricted stock units ("RSUs") of Amkor Technology, Inc. (the "Issuer") upon the Issuer's payment of a dividend on September 25, 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: 0001209191-23-050665 · doc4.xml · derivative · entry 2

ALEXANDER DOUGLAS A · CIK 0001195858 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,530.5206

Underlying: Common Stock · 28.3988 shares

Expires not disclosed

F2 · derivative.exercise_price: Represents DEUs accrued upon the payment of a dividend on September 25, 2023 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 · shares: Represents DEUs accrued upon the payment of a dividend on September 25, 2023 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 September 25, 2023 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 September 25, 2023 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.underlying_shares: Represents DEUs accrued upon the payment of a dividend on September 25, 2023 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: 0001209191-23-050665 · doc4.xml · derivative · entry 1

ALEXANDER DOUGLAS A · CIK 0001195858 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,863.3406

Underlying: Common Stock · 29.1626 shares

Expires not disclosed

F1 · derivative.exercise_price: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on September 25, 2023 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 · shares: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on September 25, 2023 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 September 25, 2023 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 September 25, 2023 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.underlying_shares: Represents dividend equivalent units ("DEUs") accrued upon the payment of a dividend on September 25, 2023 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: 0001209191-23-050042 · doc4.xml · derivative · entry 3

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,300

Underlying: Common Stock · 2,700 shares

Expires 2029-02-15

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 150,000 shares of the Issuer's common stock (the "Option Shares") was granted on February 15, 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: 0001209191-23-050042 · doc4.xml · nonDerivative · entry 2

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,394

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 February 23, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.58 to $22.84. 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: 0001209191-23-050042 · doc4.xml · nonDerivative · entry 1

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 38,094

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: 0001209191-23-049801 · doc4.xml · nonDerivative · entry 1

Qualified Annuity Trust under the Susan Y. Kim 2020-1 Irrevocable Trust Agreement dated 04/01/2020 · CIK 0001845366 · Member of 10% owner group (2)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F1 · shares: On September 14, 2023, the Reporting Person distributed 1,958,355 shares of the Common Stock of Amkor Technology, Inc. to the Family Trust under the Susan Y. Kim 2020-1 Irrevocable Trust Agreement dated 4/1/20. James J. Kim and Susan Y. Kim are co-trustees of the Reporting Person.

SEC source: 0001209191-23-049800 · doc4.xml · nonDerivative · entry 2

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

10b5-1 filing: No plan indicated

Ownership: Indirect · By Susan Y. Kim Family Trust U/A dtd. 4/1/20

Disclosed balance after: 1,958,355

F1 · shares: On September 14, 2023, the Qualified Annuity Trust under the Susan Y. Kim 2020-1 Irrevocable Trust Agreement dated 4/1/20 (the "SYK 2020 GRAT") distributed 1,958,355 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Family Trust under the Susan Y. Kim 2020-1 Irrevocable Trust Agreement dated 4/1/20 (the "SYK 2020 Family Trust"). The Reporting Person and Susan Y. Kim are co-trustees of the SYK 2020 GRAT and SYK 2020 Family 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.

F3 · balance_after: The Reporting Person is (i) a trustee of grantor retained annuity trusts of which he was the settlor and is the sole annuitant which own 1,867,747 shares of the Issuer's Common Stock, (ii) a trustee of trusts for the benefit of his immediate family members which own 13,124,330 shares of the Issuer's Common Stock, (iii) 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, and (iv) a general partner of a limited partnership which owns 39,594,980 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.

SEC source: 0001209191-23-049800 · doc4.xml · nonDerivative · entry 1

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

10b5-1 filing: No plan indicated

Ownership: Indirect · By Susan Y. Kim 2020-1 GRAT dtd. 4/1/20

Disclosed balance after: 0

F1 · shares: On September 14, 2023, the Qualified Annuity Trust under the Susan Y. Kim 2020-1 Irrevocable Trust Agreement dated 4/1/20 (the "SYK 2020 GRAT") distributed 1,958,355 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Family Trust under the Susan Y. Kim 2020-1 Irrevocable Trust Agreement dated 4/1/20 (the "SYK 2020 Family Trust"). The Reporting Person and Susan Y. Kim are co-trustees of the SYK 2020 GRAT and SYK 2020 Family Trust.

SEC source: 0001209191-23-048839 · doc4.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: 55,020,987

F1 · kind: On September 6, 2023, 915 Investments, LP sold 10,000,000 shares of Common Stock of Amkor Technology, Inc. pursuant to an underwritten secondary offering. The Reporting Person's spouse is the general partner of 915 Investments, LP.

F2 · balance_after: James J. Kim is the spouse of the Reporting Person. 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: 0001209191-23-048842 · doc4.xml · nonDerivative · entry 1

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

10b5-1 filing: No plan indicated

Ownership: Indirect · By 915 Investments, LP

Disclosed balance after: 39,594,980

F1 · kind: On September 6, 2023, 915 Investments, LP sold 10,000,000 shares of Common Stock of Amkor Technology, Inc. (the "Issuer") pursuant to an underwritten secondary offering. The Reporting Person is the general partner of 915 Investments, LP.

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.

F3 · balance_after: The Reporting Person is (i) a trustee of grantor retained annuity trusts of which he was the settlor and is the sole annuitant which own 1,867,747 shares of the Issuer's Common Stock, (ii) a trustee of trusts for the benefit of his immediate family members which own 13,124,330 shares of the Issuer's Common Stock, (iii) 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, and (iv) a general partner of a limited partnership which owns 39,594,980 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.

SEC source: 0001209191-23-048836 · doc4.xml · nonDerivative · entry 1

915 Investments, LP · CIK 0001460579 · Member of 10% owner group (2)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 39,594,980

F1 · kind: On September 6, 2023, the Reporting Person sold 10,000,000 shares of Common Stock of Amkor Technology, Inc. pursuant to an underwritten secondary offering. James J. Kim is the general partner of the Reporting Person.

SEC source: 0001209191-23-046941 · doc4.xml · derivative · entry 3

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,000

Underlying: Common Stock · 2,700 shares

Expires 2029-02-15

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 150,000 shares of the Issuer's common stock (the "Option Shares") was granted on February 15, 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: 0001209191-23-046941 · doc4.xml · nonDerivative · entry 2

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,394

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 February 23, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $24.60 to $24.93. 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: 0001209191-23-046941 · doc4.xml · nonDerivative · entry 1

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 38,094

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: 0001209191-23-043877 · doc4.xml · nonDerivative · entry 1

Qualified Annuity Trust under the John T. Kim 2018 Irrevocable Trust Agreement Dated 2/6/18 · CIK 0001732522 · Member of 10% owner group (2)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F1 · shares: On July 27, 2023, the Reporting Person distributed 498,232 shares of the Common Stock of Amkor Technology, Inc. to the Family Trust under the John T. Kim 2018 Irrevocable Trust Agreement dated 2/6/18. John T. Kim and Susan Y. Kim are co-trustees of the Reporting Person.

SEC source: 0001209191-23-043876 · doc4.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: Indirect · By trusts (excl. GRATs)

Disclosed balance after: 7,759,730

F1 · shares: On July 27, 2023, the Qualified Annuity Trust under the John T. Kim 2018 Irrevocable Trust Agreement dated 2/6/18 (the "JTK Trust") transferred 498,232 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Family Trust under the John T. Kim 2018 Irrevocable Trust Agreement dated 2/6/18 (the "Family Trust"). John T. Kim and Susan Y. Kim are co-trustees of the JTK Trust and the Family 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.

F3 · 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 7,759,730 shares of the Issuer's Common Stock, (ii) a trustee of GRATs for the benefit of members of her immediate family which own 12,923,592 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 3,338,298 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,

F4 · balance_after: (Continued from Footnote 3) (v) a manager of limited liability companies being treated as corporations for purposes of Section 16, which own 8,200,000 shares of the Issuer's Common Stock and (vi) as referenced in Footnote 5, a member of Sujoda Management, LLC, which indirectly owns 2,478,325 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.

SEC source: 0001209191-23-043876 · doc4.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 John T. Kim 2018 GRAT dtd. 2/6/18

Disclosed balance after: 0

F1 · shares: On July 27, 2023, the Qualified Annuity Trust under the John T. Kim 2018 Irrevocable Trust Agreement dated 2/6/18 (the "JTK Trust") transferred 498,232 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Family Trust under the John T. Kim 2018 Irrevocable Trust Agreement dated 2/6/18 (the "Family Trust"). John T. Kim and Susan Y. Kim are co-trustees of the JTK Trust and the Family Trust.

SEC source: 0001209191-23-043875 · doc4.xml · nonDerivative · entry 2

KIM JOHN T · CIK 0001158926 · 10% owner · Member of 10% owner group (5)

10b5-1 filing: No plan indicated

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

Disclosed balance after: 12,463,064

F1 · shares: On July 27, 2023, the Qualified Annuity Trust under the John T. Kim 2018 Irrevocable Trust Agreement dated 2/6/18 (the "JTK Trust") transferred 498,232 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Family Trust under the John T. Kim 2018 Irrevocable Trust Agreement dated 2/6/18 (the "Family Trust"). John T. Kim and Susan Y. Kim are co-trustees of the JTK Trust and the Family 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.

F3 · balance_after: The Reporting Person is (i) a trustee of family trusts for the benefit of his immediate family members which own 12,463,064 shares of the Issuer's Common Stock, (ii) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock and (iii) as referenced in footnote 4, a member of Sujoda Management, LLC, which indirectly owns 2,478,325 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.

SEC source: 0001209191-23-043875 · doc4.xml · nonDerivative · entry 1

KIM JOHN T · CIK 0001158926 · 10% owner · Member of 10% owner group (5)

10b5-1 filing: No plan indicated

Ownership: Indirect · By own 2018 GRAT dtd 2/6/18

Disclosed balance after: 0

F1 · shares: On July 27, 2023, the Qualified Annuity Trust under the John T. Kim 2018 Irrevocable Trust Agreement dated 2/6/18 (the "JTK Trust") transferred 498,232 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Family Trust under the John T. Kim 2018 Irrevocable Trust Agreement dated 2/6/18 (the "Family Trust"). John T. Kim and Susan Y. Kim are co-trustees of the JTK Trust and the Family Trust.

SEC source: 0001209191-23-043572 · doc4.xml · nonDerivative · entry 2

KIM AGNES C · CIK 0001158840 · Member of 10% owner group (5)

10b5-1 filing: No plan indicated

Ownership: Indirect · By Spouse

Disclosed balance after: 65,020,987

F4 · shares: On July 25, 2023, the JJK Trust distributed 443,811 shares of the Issuer's Common Stock to Susan Y. Kim. The Reporting Person's spouse is a trustee of the JJK Trust.

F2 · balance_after: James J. Kim is the spouse of the Reporting Person. 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: 0001209191-23-043572 · doc4.xml · nonDerivative · entry 1

KIM AGNES C · CIK 0001158840 · Member of 10% owner group (5)

10b5-1 filing: No plan indicated

Ownership: Indirect · By Spouse

Disclosed balance after: 65,464,798

F1 · shares: On July 25, 2023, the Qualified Annuity Trust under the James J. Kim 2020-1 Annuity Trust Agreement dated 04/01/20 (the "JJK Trust") distributed 443,811 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to John T. Kim. The Reporting Person's spouse is a trustee of the JJK Trust.

F2 · balance_after: James J. Kim is the spouse of the Reporting Person. 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.

F3 · balance_after: Reflects the distribution of 340,000 shares of the Issuer's Common Stock to Susan Y. Kim on June 16, 2023 by the Qualified Annuity Trust under the Susan Y. Kim 2020-1 Irrevocable Trust Agreement dated 4/1/20 (the "SYK Trust"). The Reporting Person's spouse is a trustee of the SYK Trust.

SEC source: 0001209191-23-043571 · doc4.xml · nonDerivative · entry 2

KIM JAMES J · CIK 0001158839 · Director · 10% owner · Member of 10% owner group (7)

10b5-1 filing: No plan indicated

Ownership: Indirect · By self as Trustee of own GRATs

Disclosed balance after: 1,867,747

F5 · shares: On July 25, 2023, the JJK Trust distributed 443,811 shares of the Issuer's Common Stock to Susan Y. Kim. The Reporting Person and Susan Y. Kim are co-trustees of the JJK Trust.

F3 · 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.

F4 · balance_after: The Reporting Person is (i) a trustee of grantor retained annuity trusts of which he was the settlor and is the sole annuitant which own 1,867,747 shares of the Issuer's Common Stock, (ii) a trustee of trusts for the benefit of his immediate family members which own 13,124,330 shares of the Issuer's Common Stock, (iii) 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, and (iv) a general partner of a limited partnership which owns 49,594,980 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.

SEC source: 0001209191-23-043571 · doc4.xml · nonDerivative · entry 1

KIM JAMES J · CIK 0001158839 · Director · 10% owner · Member of 10% owner group (7)

10b5-1 filing: No plan indicated

Ownership: Indirect · By self as Trustee of own GRATs

Disclosed balance after: 2,311,558

F1 · shares: On July 25, 2023, the Qualified Annuity Trust under the James J. Kim 2020-1 Qualified Annuity Trust Agreement Dated 4/1/20 (the "JJK Trust") distributed 443,811 shares of Common Stock of Amkor Technology, Inc. (the "Issuer") to John T. Kim. The Reporting Person and Susan Y. Kim are co-trustees of the JJK Trust.

F2 · balance_after: On June 27, 2023, the JJK Trust distributed 230,001 shares of the Issuer's Common Stock to the Reporting Person. Because the Reporting Person is the annuitant and a trustee of the JJK Trust, such distribution was a mere change in the form of ownership from indirect to direct and hence not reportable by the Reporting Person on a Form 4.

F3 · 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.

F4 · balance_after: The Reporting Person is (i) a trustee of grantor retained annuity trusts of which he was the settlor and is the sole annuitant which own 1,867,747 shares of the Issuer's Common Stock, (ii) a trustee of trusts for the benefit of his immediate family members which own 13,124,330 shares of the Issuer's Common Stock, (iii) 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, and (iv) a general partner of a limited partnership which owns 49,594,980 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.

SEC source: 0001209191-23-043570 · doc4.xml · nonDerivative · entry 3

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (7)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,766,234

F5 · shares: On July 25, 2023, the JJK Trust distributed 443,811 shares of the Issuer's Common Stock to the Reporting Person. Because the Reporting Person is the annuitant and a trustee of the JJK Trust, such distribution was a mere change in the form of ownership from indirect to direct and hence voluntarily reported by the Reporting Person on this Form 4.

SEC source: 0001209191-23-043570 · doc4.xml · nonDerivative · entry 2

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (7)

10b5-1 filing: No plan indicated

Ownership: Indirect · By James J. Kim 2020-1 GRAT dtd 4/1/20

Disclosed balance after: 0

F5 · shares: On July 25, 2023, the JJK Trust distributed 443,811 shares of the Issuer's Common Stock to the Reporting Person. Because the Reporting Person is the annuitant and a trustee of the JJK Trust, such distribution was a mere change in the form of ownership from indirect to direct and hence voluntarily reported by the Reporting Person on this Form 4.

SEC source: 0001209191-23-043570 · doc4.xml · nonDerivative · entry 1

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (7)

10b5-1 filing: No plan indicated

Ownership: Indirect · By James J. Kim 2020-1 GRAT dtd 4/1/20

Disclosed balance after: 443,811

F1 · shares: On July 25, 2023, the Qualified Annuity Trust under the James J. Kim 2020-1 Annuity Trust Agreement dated 4/1/20 (the "JJK Trust") distributed 443,811 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to John T. Kim. The Reporting Person and James J. Kim are co-trustees of the JJK 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.

F3 · 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 7,261,498 shares of the Issuer's common stock, (ii) a trustee of GRATs for the benefit of members of her immediate family which own 13,421,824 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 3,338,298 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,

F4 · balance_after: (Continued from Footnote 3) (v) a manager of limited liability companies being treated as corporations for purposes of Section 16, which own 8,200,000 shares of the Issuer's common stock and (vi) as referenced in Footnote 6, a member of Sujoda Management, LLC, which indirectly owns 2,478,325 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.

SEC source: 0001209191-23-043574 · doc4.xml · nonDerivative · entry 1

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

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,882,816

F1 · shares: On July 25, 2023, the Qualified Annuity Trust under the James J. Kim 2020-1 Annuity Trust Agreement dated 4/1/20 (the "JJK Trust") distributed 443,811 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to the Reporting Person. James J. Kim and Susan Y. Kim are co-trustees of the JJK Trust.

F2 · balance_after: On April 25, 2023, the Qualified Annuity Trust under the John T. Kim 2018 Irrevocable Trust Agreement dated 2/6/18 (the "JTK Trust") distributed 255,000 shares of the Issuer's Common Stock to the Reporting Person. Because the Reporting Person is the annuitant and a trustee of the JTK Trust, such distribution was a mere change in the form of ownership from indirect to direct and hence not reportable by the Reporting Person on a Form 4.

SEC source: 0001209191-23-043573 · doc4.xml · nonDerivative · entry 2

Qualified Annuity Trust under the James J. Kim 2020-1 Annuity Trust Agreement dated 04/01/2020 · CIK 0001845367 · Member of 10% owner group (3)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F2 · shares: On July 25, 2023, the Reporting Person distributed 443,811 shares of the Issuer's Common Stock to Susan Y. Kim. James J. Kim and Susan Y. Kim are the co-trustees of the Reporting Person.

SEC source: 0001209191-23-043573 · doc4.xml · nonDerivative · entry 1

Qualified Annuity Trust under the James J. Kim 2020-1 Annuity Trust Agreement dated 04/01/2020 · CIK 0001845367 · Member of 10% owner group (3)

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 443,811

F1 · shares: On July 25, 2023, the Reporting Person distributed 443,811 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to John T. Kim. James J. Kim and Susan Y. Kim are the co-trustees of the Reporting Person.

SEC source: 0001209191-23-043331 · doc4.xml · derivative · entry 3

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,700

Underlying: Common Stock · 2,700 shares

Expires 2029-02-15

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 150,000 shares of the Issuer's common stock (the "Option Shares") was granted on February 15, 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: 0001209191-23-043331 · doc4.xml · nonDerivative · entry 2

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,394

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 February 23, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $28.31 to $28.54. 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.