Sec Form 4 Filing - KIM JOHN T @ AMKOR TECHNOLOGY, INC. - 2021-05-03

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 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) 05/03/2021 (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 05/03/2021 X 20,000 ( 1 ) A $ 6.46 9,650,224 ( 2 ) D Common Stock 25,674,640 ( 3 ) ( 5 ) I By self as general partner Common Stock 15,087,774 ( 4 ) ( 5 ) I By self as trustee

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 Stock option (right to buy) $ 6.46 05/03/2021 X 20,000 ( 1 ) 05/03/2014 05/03/2021 Common Stock 20,000 $ 0 0 D

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 Mark N. Rogers, Attorney-in-Fact for John T. Kim 05/03/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On May 3, 2021, John T. Kim exercised options to purchase 20,000 shares of the Issuer's Common Stock. ( 2 )Includes options to acquire 80,000 shares of the Issuer's Common stock. ( 3 )The reporting person is one of two general partners of a limited partnership that owns 19,484,809 shares of the Issuer's Common Stock and one of three members of a limited liability company that is the general partner of a limited partnership that owns 6,189,831 shares of the Issuer's Common Stock. ( 4 )The reporting person is one of two trustees of various trusts for the benefit of his descendants, which trusts own 15,087,774 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.

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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