Sec Form 4 Filing - KIM SUSAN Y @ AMKOR TECHNOLOGY, INC. - 2023-12-19

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person KIM SUSAN Y 2. Issuer Name and Ticker or Trading Symbol AMKOR TECHNOLOGY, INC. [ AMKR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner _____ Officer (give title below) X __ Other (specify below) Member of 10% owner group (11) (Last) (First) (Middle) C/O SIANA CARR O'CONNOR & LYNAM, 1500 EAST LANCASTER AVENUE 3. Date of Earliest Transaction (MM/DD/YY) 12/19/2023 (Street) PAOLI, PA19301-9713 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 12/19/2023 G 529,650 ( 1 ) D $ 0 1,338,097 ( 2 ) ( 3 ) ( 4 ) I By James J. Kim 2021 GRAT dtd 12/15/21 Common Stock 3,434,984 ( 5 ) ( 6 ) D Common Stock 5,117,004 ( 2 ) ( 3 ) ( 4 ) I By James J. Kim 2023 GRAT dtd. 4/26/23 Common Stock 3,278,001 ( 2 ) ( 3 ) ( 4 ) I By Agnes C. Kim 2023 GRAT dtd. 4/26/23 Common Stock 2,660,840 ( 2 ) ( 3 ) ( 4 ) I By Agnes C. Kim 2020-1 GRAT dtd. 12/16/20 Common Stock 2,500,000 ( 2 ) ( 3 ) ( 4 ) ( 7 ) ( 8 ) I By own GRATs Common Stock 4,418,610 ( 2 ) ( 3 ) ( 4 ) ( 7 ) ( 8 ) I By trusts (excl. GRATs) Common Stock 19,484,809 ( 2 ) ( 3 ) ( 4 ) I By Sujochil, LP Common Stock 2,478,325 ( 2 ) ( 3 ) ( 4 ) ( 9 ) I By Sujoda Investments, LP Common Stock 0 ( 7 ) ( 8 ) I By LLCs treated as corporations Common Stock 16,710,668 ( 2 ) ( 3 ) ( 4 ) ( 7 ) ( 8 ) I By Kim Capital Partners - KPC, LLC Common Stock 39,594,980 ( 2 ) ( 3 ) ( 4 ) ( 10 ) I By 915 Investments, LP

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other KIM SUSAN Y C/O SIANA CARR O'CONNOR & LYNAM 1500 EAST LANCASTER AVENUE PAOLI, PA19301-9713 X X Member of 10% owner group (11) Signatures /s/ Brian D. Short, Attorney-in-Fact for Susan Y. Kim 12/21/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On December 19, 2023, the James J. Kim 2021 Qualified Annuity Trust Dated 12/15/21 (the "JJK Trust") distributed 529,650 shares of the Common Stock of Amkor Technology, Inc. (the "Issuer") to James J. Kim. The Reporting Person and James J. Kim are co-trustees of the JJK Trust. ( 2 )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 of the Securities Exchange Act of 1934, as amended ("Section 16"), or for any other purpose. ( 3 )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 4,418,610 shares of the Issuer's Common Stock; (ii) a trustee of GRATs for the benefit of members of her immediate family which own 12,393,942 shares of the Issuer's Common Stock; (iii) a trustee of GRATs of which the Reporting Person was the settlor and is the sole annuitant which own 2,500,000 shares of the Issuer's Common Stock; (iv) a general partner of a limited partnership (Sujochil, LP) which owns 19,484,809 shares of the Issuer's Common Stock; ( 4 )(Continued from Footnote 3) (v) a manager of a limited liability company being treated as a corporation for purposes of Section 16 which owns 16,710,668 shares of the Issuer's Common Stock; (vi) as referenced in Footnote 9, a member of Sujoda Management, LLC, which indirectly owns 2,478,325 shares of the Issuer's Common Stock and (vii) 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. ( 5 )Reflects the Qualified Annuity Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dtd 8/29/18 (the "SYK 2018 GRAT") distribution of 168,750 shares of the Issuer's Common Stock to the Reporting Person on October 11, 2023. Because the Reporting Person is the annuitant and a trustee of the SYK 2018 GRAT, 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. ( 6 )Reflects the Reporting Person's distribution of 2,000,000 shares of the Issuer's Common Stock to Kim Capital Partners - KCP, LLC ("KCP LLC" ) on November 14, 2023. Because the Reporting Person is a manager of KCP LLC, such distribution was a mere change in the form of ownership from direct to indirect and hence not reportable by the Reporting Person on a Form 4. ( 7 )Reflects the distribution to KCP LLC on November 14, 2023 of (i) 2,000,000 shares of the Issuer's Common Stock by the Reporting Person; (ii) 2,733,333 shares of the Issuer's Common Stock by Alexandra Investments, LLC; (iii) 2,733,333 shares of the Issuer's Common stock by Jacqueline Investments, LLC; (iv) 2,733,334 shares of the Issuer's Common Stock by Dylan Investments, LLC; (v) 1,958,355 shares of the Issuer's Common Stock by the Family Trust under the Susan Y. Kim 2020-1 Irrevocable Trust Agreement dtd. 4/1/20; (vi) 1,211,193 shares of the Issuer's Common Stock by the Family Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement dtd. 8/29/18 and (vii) 3,341,120 shares of the Issuer's Common Stock by the Family Trust Under the Susan Y. Kim 2012 Irrevocable Trust Agreement dtd. 7/26/12. ( 8 )Because the Reporting Person is a manager or trustee of each of the entities that distributed to KCP LLC and a manager of KCP LLC, such distributions were a mere change in the form of ownership and hence not reportable on a Form 4. ( 9 )The sole general partner of Sujoda Investments, LP is Sujoda Management, LLC. The Reporting Person is one of three members of Sujoda Management, LLC. Sujoda Management, LLC is being treated as a limited partnership for purposes of Section 16, and, pursuant to the Form 4 instructions, the Reporting Person has elected to treat all of the shares of the Issuer's common stock owned by Sujoda Investments, LP as beneficially owned by the Reporting Person. ( 10 )The Reporting Person was appointed general partner of 915 Investments, LP on October 30, 2023. Because this appointment did not involve the transfer of securities, it was not reportable as a transaction on a Form 4.

Remarks: (11) The Reporting Person states that the filing of this Form 4 shall not be deemed an admission that the Reporting Person is the beneficial owner of the reported securities owned by the other members of the group, for the purpose of Section 16 or for any other purpose.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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