Sec Form 5 Filing - KIM SUSAN Y @ AMKOR TECHNOLOGY, INC. - 2020-12-31

FORM 5 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) See Exhibit 99.1 (Last) (First) (Middle) C/O SIANA CARR O'CONNOR & LYNAM,, 1500 EAST LANCASTER AVENUE 3. Date of Earliest Transaction (MM/DD/YY) 12/31/2020 (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 03/02/2020 G( 1 ) V 91,392 D $ 10.28 32,339,816 ( 7 ) I By self as trustee Common Stock 03/16/2020 G( 2 ) V 15,641 D $ 7.47 32,339,816 ( 7 ) I By self as trustee Common Stock 03/16/2020 G( 2 ) V 15,641 A $ 7.47 4,638,381 ( 8 ) ( 9 ) ( 10 ) D Common Stock 05/26/2020 G( 3 ) V 1,564,323 A $ 10.33 32,339,816 ( 7 ) I By self as trustee Common Stock 08/21/2020 G( 4 ) V 561,343 D $ 12.71 32,339,816 ( 7 ) I By self as trustee Common Stock 08/21/2020 G( 4 ) V 561,343 A $ 12.71 32,339,816 ( 7 ) I By self as trustee Common Stock 12/15/2020 G( 5 ) V 727,169 D $ 15.4 32,339,816 ( 7 ) I By self as trustee Common Stock 12/15/2020 G( 6 ) V 446,316 D $ 15.4 32,339,816 ( 7 ) I By self as trustee Common Stock 25,674,640 ( 7 ) I By self as GP

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 See Exhibit 99.1 Signatures /s/ Mark N. Rogers, as Attorney in Fact 02/12/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On March 2, 2020, the James J. Kim Qualified Annuity Trust U/A Dated 10/13/14 distributed 91,392 shares of the Issuer's Common Stock to James J. Kim. James J. Kim and Susan Y. Kim are co-trustees. ( 2 )On March 16, 2020, the James J. Kim Qualified Annuity Trust U/A Dated 10/13/14 distributed 15,641 shares of the Issuer's Common Stock to each of Susan Y. Kim, John T. Kim and David D. Kim. James J. Kim and Susan Y. Kim are co-trustees. ( 3 )On May 26, 2020, James J. Kim transferred 1,564,323 shares of the Issuer's Common Stock to the James J. Kim 2020-1 Qualified Annuity Trust under the James J. Kim 2020-1 Qualified Annuity Trust Agreement dated 4/1/20. Susan Y. Kim and James J. Kim are co-trustees. ( 4 )On August 21, 2020, the Susan Y. Kim 2015 Irrevocable Trust U/A Dated 3/16/15 distributed 561,343 shares of the Issuer's Common Stock to the Family Trust Under the Susan Y. Kim 2012 Irrevocable Trust Agreement Dated 7/26/12. Susan Y. Kim and John T. Kim are co-trustees of both of the trusts. ( 5 )On December 15, 2020, the James J. Kim 2019-1 Qualified Annuity Trust U/A Dated 9/10/19 distributed 727,169 shares of the Issuer's Common Stock to James J. Kim. James J. Kim and Susan Y. Kim are co-trustees of the trust. ( 6 )On December 15, 2020, the James J. Kim 2018-1 Qualified Annuity Trust U/A Dated 8/30/18 distributed 446,316 shares of the Issuer's Common Stock to James J. Kim. James J. Kim and Susan Y. Kim are co-trustees of the trust. ( 7 )The reporting person may be deemed to indirectly own 27,717,773 shares of the Issuer's Common Stock held by various family trusts of which the reporting person is a trustee, 4,622,043 shares of the Issuer's Common Stock held by grantor retained annuity trusts (see footnote 9), and 25,674,640 shares of the Issuer's Common Stock held by limited partnerships established for the benefit of members of the James J. Kim family of which the reporting person is a general partner. 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, or for any other purpose. ( 8 )Includes options to acquire 125,000 shares of the Issuer's Common Stock. ( 9 )On April 1, 2020, the reporting person gifted 3,000,000 shares of the Issuer's Common Stock to the Qualified Annuity Trust Under the Susan Y. Kim 2020-1 Irrevocable Trust Agreement Dated 04/01/20. Susan Y. Kim and James J. Kim are co-trustees of the trust. On August 19, 2020, the Susan Y. Kim 2015 Irrevocable Trust U/A Dated 3/16/15 distributed 526,500 shares of the Issuer's Common Stock to the reporting person. Susan Y. Kim and John T. Kim are co-trustees of the trust. On December 15, 2020, the Qualified Annuity Trust under the Susan Y. Kim 2018-1 Irrevocable Trust Agreement Dated 8/29/18 distributed 162,257 shares of the Issuer's Common Stock to the reporting person. James J. Kim and Susan Y. Kim are co-trustees of the trust. ( 10 )(Continued From Footnote 9) Each of the aforementioned trusts to which the reporting person transferred shares of the Issuer's Common Stock or from which the reporting person received such shares is a grantor retained annuity trust of which the reporting person is the settlor, the sole current beneficiary and a co-trustee. Pursuant to the Form 5 instructions, in her capacity as a co-trustee of the trusts, the reporting person is being treated as having a pecuniary interest in all of the shares held by such trusts. Accordingly, transfers between the reporting person and such trusts result in mere changes from direct to indirect ownership or vice versa. Such transfers are therefore not reported on this Form 5. On December 31, 2020, such grantor retained annuity trusts held 4,622,043 shares of the Issuer's Common Stock.

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