Sec Form 5 Filing - KIM JOHN T @ 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 JOHN T 2. Issuer Name and Ticker or Trading Symbol AMKOR TECHNOLOGY, INC. [ AMKR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) X __ Other (specify below) 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 03/16/2020 G( 1 ) V 15,641 A $ 7.47 2,056,223 ( 2 ) ( 3 ) ( 4 ) D Common Stock 22,681,775 ( 2 ) ( 3 ) ( 5 ) I By self as trustee Common Stock 25,674,640 ( 5 ) ( 6 ) 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 JOHN T C/O SIANA CARR O'CONNOR & LYNAM, 1500 EAST LANCASTER AVENUE PAOLI, PA19301-9713 X 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 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. ( 2 )On July 1, 2020, 278,833 shares of the Issuer's Common Stock were distributed by the Qualified Annuity Trust under the John T. Kim 2018 Irrevocable Trust Agreement Dated February 6, 2018 to the reporting person. Susan Y. Kim and John T. Kim are co-trustees of the trust. The aforementioned trust 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 his capacity as a co-trustee of the trust, the reporting person is being treated as having a pecuniary interest in all of the shares held by such trust. ( 3 )(Continued From Footnote 2) Accordingly, the transfer between the reporting person and such trust results in a mere change from indirect ownership to direct ownership. Such transfer is therefore not reported on this Form 5. On December 31, 2020, such grantor retained annuity trusts created by the reporting person held 1,202,942 shares of the Issuer's Common Stock. ( 4 )Includes options to acquire 100,000 shares of the Issuer's Common Stock. ( 5 )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. ( 6 )The reporting person may be deemed to indirectly own 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.

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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