AMKR

SEC source: 0000899243-22-000398 · doc4.xml · nonDerivative · entry 3

SUJODA Investments, LP · CIK 0001509340 · Member of 10% owner group (5)

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,478,325

F3 · kind: On December 30, 2021, the reporting person transferred 668,666 shares of the Issuer's Common stock to Agnes C. Kim and 668,666 shares of the Issuer's Common stock to James J. Kim in partial payment of the principal of a Note.

F4 · kind: The general partner of the reporting person is Sujoda Management, LLC, whose members are Susan Y. Kim, John T. Kim and David D. Kim.

SEC source: 0000899243-22-000398 · doc4.xml · nonDerivative · entry 2

SUJODA Investments, LP · CIK 0001509340 · Member of 10% owner group (5)

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,815,657

F2 · kind: On December 30, 2021, the reporting person transferred 1,187,087 shares of the Issuer's Common stock to James J. Kim in payment of the principal of a Note.

F4 · kind: The general partner of the reporting person is Sujoda Management, LLC, whose members are Susan Y. Kim, John T. Kim and David D. Kim.

SEC source: 0000899243-22-000398 · doc4.xml · nonDerivative · entry 1

SUJODA Investments, LP · CIK 0001509340 · Member of 10% owner group (5)

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,002,744

F1 · kind: On December 30, 2021, the reporting person transferred 1,187,087 shares of the Issuer's Common stock to Agnes C. Kim in payment of the principal of a Note.

F4 · kind: The general partner of the reporting person is Sujoda Management, LLC, whose members are Susan Y. Kim, John T. Kim and David D. Kim.

SEC source: 0000899243-22-002858 · doc4.xml · nonDerivative · entry 10

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (15)

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,249,884

F9 · shares: On December 27, 2021, the reporting person transferred 164,678 shares of the Issuer's Common Stock to Susins, LLC. Susins, LLC is being treated as a corporation for purposes of Section 16 of the Securities Exchange Act of 1934, as amended ("Section 16"). Its managers are John T. Kim and Liam E. Blaney.

SEC source: 0000899243-22-002821 · doc4.xml · nonDerivative · entry 5

KIM AGNES C · CIK 0001158840 · Member of 10% owner group (6)

10b5-1 filing: Not disclosed

Ownership: Indirect · By spouse

Disclosed balance after: 74,546,118

F4 · shares: On December 27, 2021, Susan Y. Kim transferred 164,678 shares of the Issuer's Common Stock to Susins, LLC. Susins, LLC is being treated as a corporation for purposes of Section 16 of the Securities and Exchange Act of 1934, as amended ("Section 16"). The Susan Y. Kim 2012 Generation-Skipping Trust U/A dated December 11, 2012 is being treated as a controlling shareholder of Susins, LLC. James J. Kim is a trustee of said trust and members of his immediate family are beneficiaries thereof.

F5 · 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, or for any other purpose.

SEC source: 0000899243-22-002809 · doc4.xml · nonDerivative · entry 1

Susins, LLC · CIK 0001901981 · Member of 10% owner group (2)

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 164,678

F1 · shares: On December 27, 2021, Susan Y. Kim transferred 164,678 shares of the Issuer's Common Stock to the reporting person without consideration. The reporting person is treated as a corporation for purposes of Section 16 of the Securities Exchange Act of 1934, as amended ("Section 16"). John T. Kim and Liam E. Blaney are the managers of the reporting person.

SEC source: 0000899243-22-002803 · doc4.xml · nonDerivative · entry 4

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

10b5-1 filing: Not disclosed

Ownership: Indirect · By Susan Y. Kim 2012 Generation-Skipping Trust

Disclosed balance after: 164,678

F4 · shares: On December 27, 2021, Susan Y. Kim transferred 164,678 shares of the Issuer's Common Stock to Susins, LLC. Susins, LLC is being treated as a corporation for purposes of Section 16 of the Securities Exchange Act of 1934, as amended ("Section 16"). The Susan Y. Kim 2012 Generation-Skipping Trust Dated December 11, 2012 is being treated as a controlling shareholder of Susins, LLC. The reporting person is a trustee of said trust and members of his immediate family are beneficiaries thereof. The reporting person's indirect holding of these 164,678 shares of the Issuer's Common Stock was inadvertently omitted from his Form 4 that was filed with the Commission on January 4, 2022.

F6 · balance_after: Pursuant to the Form 4 instructions, the reporting person is being treated as having a pecuniary interest in all of the shares held by these trusts and partnerships. 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, or for any other purpose.

SEC source: 0000899243-22-003080 · doc4.xml · nonDerivative · entry 1

Susan Y. Kim 2012 Generation-Skipping Trust U/A Dated December 11, 2012 · CIK 0001906242 · Member of 10% owner group (2)

10b5-1 filing: Not disclosed

Ownership: Indirect · By Susins, LLC

Disclosed balance after: 164,678

F1 · shares: On December 27, 2021, Susan Y. Kim transferred 164,678 shares of the Issuer's Common Stock to Susins, LLC without consideration. Susins, LLC is treated as a corporation for purposes of Section 16 of the Securities Exchange Act of 1934, as amended ("Section 16"). The reporting person is being treated as a controlling shareholder of Susins, LLC. John T. Kim and Liam E. Blaney are the managers of Susins, LLC.

SEC source: 0000899243-22-015250 · doc4a.xml · nonDerivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Indirect · By trusts (excl. own GRATs & Susan Y. Kim 2018-1 Qualified Annuity Trust dtd. 8/29/18)

Disclosed balance after: 12,678,815

F1 · shares: On January 27, 2022, the Reporting Person filed a Form 4 (the "Original Form 4") which inadvertently omitted a transaction which resulted in an increase in the indirect holdings of the Reported Person as the trustee of a trust for the benefit of members of the Reporting Person's immediate family. On December 27, 2021, a transfer of 164,678 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") was made to a limited liability company being treated as a corporation for purposes of Section 16 of the Securities Exchange Act of 1934, as amended ("Section 16"). The Reporting Person is a trustee of a trust which is a member of such limited liability company. The beneficiaries of the trust are members of the Reporting Person's immediate family. The trust is being treated as the "controlling shareholder" of the limited liability company for purposes of Section 16.

F2 · shares: (Continued from Footnote 1) Although the above described transfer of shares of the Issuer's Common Stock was not reported on the Original Form 4, such shares were correctly included in the indirect holdings of the Reporting Person on the Original Form 4

F3 · balance_after: The Reporting Person is a trustee of trusts for the benefit of his immediate family members (excluding his own grantor retained annuity trusts and the Qualified Annuity Trust Under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dtd 8/29/18) which own 12,678,815 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. 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, or for any other purpose.

SEC source: 0000899243-21-049718 · doc4.xml · nonDerivative · entry 1

KIM JAMES J · CIK 0001158839 · Director · 10% owner · See Exhibit 99.1

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 460,799

F1 · balance_after: The reporting transaction involved the withholding of 94 shares of the Issuer's Common Stock upon the early vesting of an equal number of restricted stock units. In accordance with the relevant plan and award agreement, the shares were withheld in order to pay taxes associated with the reporting person's becoming retirement eligible. The total reported in Column 5 includes 10,799 previously reported restricted stock units and previously reported options to purchase 450,000 shares of the Issuer's Common Stock..

SEC source: 0001209191-21-071107 · doc4.xml · nonDerivative · entry 1

Stone John Charles · CIK 0001581432 · Executive Vice President

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,493

F1 · balance_after: The reporting transaction involved the withholding of 59 shares of stock issuable upon the early vesting of an equal number of restricted stock units to pay taxes associated with the reporting person becoming retirement eligible. The total reported in Column 5 includes 6,477 previously reported restricted stock units.

SEC source: 0001209191-21-071105 · doc4.xml · nonDerivative · entry 1

Haghighi Farshad · CIK 0001887579 · Executive Vice President

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,529

F1 · balance_after: The reporting transaction involved the withholding of 20 shares of stock issuable upon the early vesting of an equal number of restricted stock units to pay taxes associated with the reporting person becoming retirement eligible. The total reported in Column 5 includes 2,703 previously reported restricted stock units.

SEC source: 0001209191-21-070341 · doc4.xml · derivative · entry 3

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 134,500

Underlying: Common Stock · 5,000 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 "Grant Date") and vests over four years as follows: (i) with respect to 25% of the Option Shares, on the first anniversary of the Grant Date; and (ii) with respect to the remainder of the Option Shares, in equal quarterly installments thereafter, such that 100% of the Option will vest on the fourth anniversary of the Grant Date.

SEC source: 0001209191-21-070341 · doc4.xml · nonDerivative · entry 2

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 14,844

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 11, 2021.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.68 to $23.29.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: 0001209191-21-070341 · doc4.xml · nonDerivative · entry 1

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,844

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: 0001209191-21-070343 · doc4.xml · derivative · entry 3

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 242,500

Underlying: Common Stock · 10,000 shares

Expires 2030-07-30

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 (the "Option") to acquire 375,000 shares of the Issuer's common stock was granted on July 30, 2020 (the "Grant Date") and will vest in equal quarterly installments over three years, such that 100% of the Option will be vested on the third anniversary of the Grant Date.

SEC source: 0001209191-21-070343 · doc4.xml · nonDerivative · entry 2

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 320,000

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 May 13, 2021.

SEC source: 0001209191-21-070343 · doc4.xml · nonDerivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 345,000

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: 0000899243-22-002858 · doc4.xml · nonDerivative · entry 9

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (15)

10b5-1 filing: Not disclosed

Ownership: Indirect · By James J. Kim GRAT dtd 12/15/21

Disclosed balance after: 2,353,347

F8 · shares: On December 15, 2021, James J. Kim transferred 596,920 shares of the Issuer's Common Stock to the James J. Kim 2021 Qualified Annuity Trust U/A Dated 12/15/2021.

F11 · balance_after: Pursuant to the Form 4 instructions, the reporting person is being treated as having a pecuniary interest in all of these shares. 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, or for any other purpose.

SEC source: 0000899243-22-002858 · doc4.xml · nonDerivative · entry 8

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (15)

10b5-1 filing: Not disclosed

Ownership: Indirect · By James J. Kim GRAT dtd 9/10/19

Disclosed balance after: 2,675,911

F7 · shares: On December 15, 2021, the Qualified Annuity Trust under the James J. Kim 2019-1 Qualified Annuity Trust Agreement dtd September 10, 2019 distributed 596,920 shares of the Issuer's Common Stock to James J. Kim. James J. Kim and Susan Y. Kim are the co-trustees of the trust.

F11 · balance_after: Pursuant to the Form 4 instructions, the reporting person is being treated as having a pecuniary interest in all of these shares. 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, or for any other purpose.

SEC source: 0000899243-22-002858 · doc4.xml · nonDerivative · entry 7

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (15)

10b5-1 filing: Not disclosed

Ownership: Indirect · By James J. Kim GRAT dtd 12/15/21

Disclosed balance after: 1,756,427

F6 · shares: On December 15, 2021, James J. Kim transferred 1,756,427 shares of the Issuer's Common Stock to the James J. Kim 2021 Qualified Annuity Trust U/A Dated 12/15/2021. James J. Kim and the reporting person are the co-trustees of the trust.

F11 · balance_after: Pursuant to the Form 4 instructions, the reporting person is being treated as having a pecuniary interest in all of these shares. 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, or for any other purpose.

SEC source: 0000899243-22-002820 · doc4.xml · nonDerivative · entry 1

Qualified Annuity Trust under the James J. Kim 2019-1 Qualified Annuity Trust Agreement dtd September10,2019 · CIK 0001792394 · Member of 10% owner group (2)

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,675,911

F1 · shares: On December 15, 2021, the reporting person distributed 596,920 shares of the Issuer's Common Stock to James J. Kim. James J. Kim and Susan Y. Kim are the co-trustees of the trust.

SEC source: 0000899243-22-003078 · doc4.xml · nonDerivative · entry 2

James J. Kim 2021 Qualified Annuity Trust U/A Dated 12/15/2021 · CIK 0001906235 · Member of 10% Owner Group (3)

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,353,347

F2 · shares: On December 15, 2021, James J. Kim transferred 596,920 shares of the Issuer's Common Stock to the reporting person.

SEC source: 0000899243-22-003078 · doc4.xml · nonDerivative · entry 1

James J. Kim 2021 Qualified Annuity Trust U/A Dated 12/15/2021 · CIK 0001906235 · Member of 10% Owner Group (3)

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,756,427

F1 · shares: On December 15, 2021, James J. Kim transferred 1,756,427 shares of the Issuer's Common Stock to the reporting person. James J. Kim and Susan Y. Kim are the co-trustees of the trust.

SEC source: 0001209191-21-067313 · doc4.xml · derivative · entry 3

CHURCHILL WINSTON J · CIK 0000923792 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 20,000 shares

Expires 2029-05-15

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.

F2 · derivative.exercise_date: This stock option (the "Option") to acquire 20,000 shares of the Issuer's common stock (the "Option Shares") was granted on May 15, 2019 (the "Grant Date") and vested with respect to 100% of the Option Shares on the earlier of the the first anniversary of the Grant Date or the date of the first annual meeting of the Company immediately following the Grant Date.

SEC source: 0001209191-21-067313 · doc4.xml · nonDerivative · entry 2

CHURCHILL WINSTON J · CIK 0000923792 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 14,394

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.40 to $22.47. 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: 0001209191-21-067313 · doc4.xml · nonDerivative · entry 1

CHURCHILL WINSTON J · CIK 0000923792 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 34,394

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: 0001209191-21-065930 · doc4.xml · derivative · entry 4

Stone John Charles · CIK 0001581432 · Executive Vice President

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 46,875

Underlying: Common Stock · 9,375 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.

F2 · derivative.exercise_date: This stock option (the "Option") to acquire 150,000 shares of the common stock of Amkor Technology, Inc. (the "Option Shares") was granted on February 15, 2019 (the "Grant Date") and vests over four years as follows: (i) with respect to 25% of the Option Shares, on the first anniversary of the Grant Date; and (ii) with respect to the remainder of the Option Shares, in equal quarterly installments thereafter, such that 100% of the Option will vest on the fourth anniversary of the Grant Date.

SEC source: 0001209191-21-065930 · doc4.xml · nonDerivative · entry 2

Stone John Charles · CIK 0001581432 · Executive Vice President

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,552

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 30, 2021.

SEC source: 0001209191-21-065930 · doc4.xml · nonDerivative · entry 1

Stone John Charles · CIK 0001581432 · Executive Vice President

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 40,927

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: 0001209191-21-065915 · doc4.xml · derivative · entry 3

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 139,500

Underlying: Common Stock · 5,000 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 "Grant Date") and vests over four years as follows: (i) with respect to 25% of the Option Shares, on the first anniversary of the Grant Date; and (ii) with respect to the remainder of the Option Shares, in equal quarterly installments thereafter, such that 100% of the Option will vest on the fourth anniversary of the Grant Date.

SEC source: 0001209191-21-065915 · doc4.xml · nonDerivative · entry 2

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 14,844

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 11, 2021.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $24.47 to $24.77.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: 0001209191-21-065915 · doc4.xml · nonDerivative · entry 1

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,844

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: 0001209191-21-064842 · doc4.xml · derivative · entry 3

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 252,500

Underlying: Common Stock · 10,000 shares

Expires 2030-07-30

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 375,000 shares of the Issuer's common stock was granted on July 30, 2020 (the "Grant Date") and will vest in equal quarterly installments over three years, such that 100% of the Option will be vested on the third anniversary of the Grant Date.

SEC source: 0001209191-21-064842 · doc4.xml · nonDerivative · entry 2

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 335,000

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 May 13, 2021.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $23.12 to $23.54.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.

SEC source: 0001209191-21-064842 · doc4.xml · nonDerivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 360,000

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: 0001209191-21-061403 · doc4.xml · derivative · entry 3

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 144,500

Underlying: Common Stock · 5,000 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 "2019 Option") to acquire 150,000 shares of the Issuer's common stock (the "2019 Option Shares") was granted on February 15, 2019 (the "2019 Grant Date") and vests over four years as follows: (i) with respect to 25% of the 2019 Option Shares, on the first anniversary of the 2019 Grant Date; and (ii) with respect to the remainder of the 2019 Option Shares, in equal quarterly installments thereafter, such that 100% of the 2019 Option will vest on the fourth anniversary of the 2019 Grant Date.

SEC source: 0001209191-21-061403 · doc4.xml · nonDerivative · entry 2

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 14,844

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 11, 2021.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.77 to $23.15.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: 0001209191-21-061403 · doc4.xml · nonDerivative · entry 1

Faust Megan · CIK 0001684564 · CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,844

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: 0001209191-21-060770 · doc4.xml · derivative · entry 3

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 262,500

Underlying: Common Stock · 10,000 shares

Expires 2030-07-30

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 375,000 shares of the Issuer's common stock was granted on July 30, 2020 (the "Grant Date") and will vest in equal quarterly installments over three years, such that 100% of the Option will be vested on the third anniversary of the Grant Date.

SEC source: 0001209191-21-060770 · doc4.xml · nonDerivative · entry 2

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 350,000

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 May 13, 2021.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.30 to $22.85.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: 0001209191-21-060770 · doc4.xml · nonDerivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 375,000

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: 0000899243-22-002762 · doc4.xml · nonDerivative · entry 3

Qualified Annuity Trust under the James J. Kim 2018-1 Qualified Annuity Trust Agreement dtd 8/30/18 · CIK 0001752917 · Member of 10% owner group (4)

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

F3 · shares: On October 4, 2021, the reporting person distributed 626,192 shares of the Issuer's Common Stock to John T. Kim.

SEC source: 0000899243-22-002762 · doc4.xml · nonDerivative · entry 2

Qualified Annuity Trust under the James J. Kim 2018-1 Qualified Annuity Trust Agreement dtd 8/30/18 · CIK 0001752917 · Member of 10% owner group (4)

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 626,192

F2 · shares: On October 4, 2021, the reporting person distributed 626,192 shares of the Issuer's Common Stock to Susan Y. Kim.

SEC source: 0000899243-22-002858 · doc4.xml · nonDerivative · entry 6

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (15)

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,414,562

F5 · shares: On October 4, 2021, the Qualified Annuity Trust under the James J. Kim 2018-1 Qualified Annuity Trust Agreement dtd 8/30/18 distributed 626,192 shares of the Issuer's Common Stock to the reporting person.

SEC source: 0000899243-22-002858 · doc4.xml · nonDerivative · entry 5

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (15)

10b5-1 filing: Not disclosed

Ownership: Indirect · By James J. Kim GRAT dtd 8/30/18

Disclosed balance after: 0

F5 · shares: On October 4, 2021, the Qualified Annuity Trust under the James J. Kim 2018-1 Qualified Annuity Trust Agreement dtd 8/30/18 distributed 626,192 shares of the Issuer's Common Stock to the reporting person.

SEC source: 0000899243-22-002858 · doc4.xml · nonDerivative · entry 4

KIM SUSAN Y · CIK 0001158922 · Director · 10% owner · Member of 10% owner group (15)

10b5-1 filing: Not disclosed

Ownership: Indirect · By James J. Kim GRAT dtd 8/30/18

Disclosed balance after: 626,192

F4 · shares: On October 4, 2021, the Qualified Annuity Trust under the James J. Kim 2018-1 Qualified Annuity Trust Agreement dtd 8/30/18 distributed 626,192 shares of the Issuer's Common Stock to John T. Kim.

F11 · balance_after: Pursuant to the Form 4 instructions, the reporting person is being treated as having a pecuniary interest in all of these shares. 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, or for any other purpose.

SEC source: 0000899243-22-002821 · doc4.xml · nonDerivative · entry 3

KIM AGNES C · CIK 0001158840 · Member of 10% owner group (6)

10b5-1 filing: Not disclosed

Ownership: Indirect · By spouse

Disclosed balance after: 74,381,440

F3 · shares: On October 4, 2021, the Qualified Annuity Trust under the James J. Kim 2018-1 Qualified Annuity Trust Agreement dtd 8/30/18 distributed 626,192 shares of the Issuer's Common Stock to John T. Kim. James J. Kim and John T. Kim are father and son.

F5 · 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, or for any other purpose.

SEC source: 0000899243-22-002821 · doc4.xml · nonDerivative · entry 2

KIM AGNES C · CIK 0001158840 · Member of 10% owner group (6)

10b5-1 filing: Not disclosed

Ownership: Indirect · By spouse

Disclosed balance after: 75,007,632

F2 · shares: On October 4, 2021, the Qualified Annuity Trust under the James J. Kim 2018-1 Qualified Annuity Trust Agreement dtd 8/30/18 distributed 626,192 shares of the Issuer's Common Stock to Susan Y. Kim. James J. Kim and Susan Y. Kim are the co-trustees of the trust.

F5 · 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, or for any other purpose.

SEC source: 0000899243-22-002803 · doc4.xml · nonDerivative · entry 3

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

10b5-1 filing: Not disclosed

Ownership: Indirect · By James J. Kim 2018-1 GRAT

Disclosed balance after: 0

F3 · shares: On October 4, 2021, the Qualified Annuity Trust under the James J. Kim 2018-1 Qualified Annuity Trust Agreement dtd 8/30/18 distributed 626,192 shares of the Issuer's Common Stock to John T. Kim. The reporting person and John T. Kim are father and son.