Sec Form 4 Filing - KIM AGNES C @ AMKOR TECHNOLOGY, INC. - 2023-02-22

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

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person KIM AGNES C 2. Issuer Name and Ticker or Trading Symbol AMKOR TECHNOLOGY, INC. [ AMKR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 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) 02/22/2023 (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 02/22/2023 J V 384,000 A $ 25.28 69,793,857 ( 1 ) ( 2 ) I By spouse Common Stock 02/22/2023 J V 384,000 A $ 25.28 70,177,857 ( 2 ) ( 3 ) I By spouse Common Stock 02/22/2023 J V 384,000 A $ 25.28 70,561,857 ( 2 ) ( 4 ) I By spouse Common Stock 02/22/2023 J V 384,000 A $ 25.28 70,945,857 ( 2 ) ( 5 ) I By spouse Common Stock 02/22/2023 J V 384,000 A $ 25.28 71,329,857 ( 2 ) ( 6 ) I By spouse Common Stock 02/22/2023 A( 7 ) 59,477 A $ 0 71,389,334 ( 2 ) I By spouse Common Stock 02/22/2023 F( 8 ) 25,267 D $ 25.28 71,364,067 ( 2 ) I By spouse Common Stock 02/24/2023 M 2,599 A $ 0 ( 9 ) 71,366,666 ( 2 ) I By spouse Common Stock 02/24/2023 F( 10 ) 1,053 D $ 25.27 71,365,613 ( 2 ) I By spouse Common Stock 3,278,001 D

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 Restricted Stock Units $ 0 ( 9 ) 02/24/2023 M 2,599 ( 9 ) ( 9 ) Common Stock 2,599 $ 0 8,149 I By spouse

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other KIM AGNES C C/O SIANA CARR O'CONNOR & LYNAM 1500 EAST LANCASTER AVENUE PAOLI, PA19301-9713 Member of 10% owner group (11) Signatures Mark N. Rogers, Attorney-in-Fact for Agnes C. Kim 02/24/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On February 22, 2023, the Irrevocable Deed of Trust of James J. Kim for Alexandra Kim Panichello dated 12/24/92 sold 384,000 shares of Common Stock of Amkor Technology, Inc. (the "Issuer") to James J. Kim in full payment of the principal and accrued interest of a note payable to Mr. Kim by such trust. Mr. Kim is the spouse of the Reporting Person. This transaction is exempt pursuant to Section 16 of the Securities Exchange Act of 1934, as amended ("Section 16"), and is voluntarily reported. ( 2 )James J. Kim is the spouse of the Reporting Person. 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. ( 3 )On February 22, 2023, the Irrevocable Deed of Trust of James J. Kim for Allyson Lee Kim dated 10/15/01 sold 384,000 shares of the Issuer's Common Stock to James J. Kim in full payment of the principal and accrued interest of a note payable to Mr. Kim by such trust. Mr. Kim is the spouse of the Reporting Person. This transaction is exempt pursuant to Section 16 and is voluntarily reported. ( 4 )On February 22, 2023, the Irrevocable Deed of Trust of James J. Kim for Dylan James Panichello dated 10/15/01 sold 384,000 shares of the Issuer's Common Stock to James J. Kim in full payment of the principal and accrued interest of a note payable to Mr. Kim by such trust. Mr. Kim is the spouse of the Reporting Person. This transaction is exempt pursuant to Section 16 and is voluntarily reported. ( 5 )On February 22, 2023, the Irrevocable Deed of Trust of James J. Kim for Jacqueline Mary Panichello dated 10/3/94 sold 384,000 shares of the Issuer's Common Stock to James J. Kim in full payment of the principal and accrued interest of a note payable to Mr. Kim by such trust. Mr. Kim is the spouse of the Reporting Person. This transaction is exempt pursuant to Section 16 and is voluntarily reported. ( 6 )On February 22, 2023, the Irrevocable Deed of Trust of James J. Kim, Settlor, FBO Jason Lee Kim dated 11/17/03 sold 384,000 shares of the Issuer's Common Stock to James J. Kim in full payment of the principal and accrued interest of a note payable to Mr. Kim by such trust. Mr. Kim is the spouse of the Reporting Person. This transaction is exempt pursuant to Section 16 and is voluntarily reported. ( 7 )This Form 4 reports the vesting on February 22, 2023 of 59,477 shares of the Issuer's Common Stock underlying performance-vested restricted stock units ("PSUs") granted to the spouse of the Reporting Person on February 11, 2021 pursuant to the Issuer's Second Amended and Restated 2007 Equity Incentive Plan, as amended, and the related award agreement. The PSUs vested based on the attainment of a basic cumulative earnings per share performance goal over a two-year performance period beginning January 1, 2021 and ending on December 31, 2022. ( 8 )The transaction represents shares of the Issuer's Common Stock withheld by the Issuer in connection with the vesting of PSUs to satisfy the tax withholding obligations of the Reporting Person's spouse. The Issuer will pay these taxes on behalf of the Reporting Person's spouse. ( 9 )On February 24, 2022 (the "RSU Grant Date"), the Reporting Person's spouse was granted 10,748 time-vested restricted stock units ("RSUs") pursuant to the Issuer's 2021 Equity Incentive Plan, as amended, and the applicable award agreement. The RSUs convert into shares of the Issuer's Common Stock on a one-to-one basis and vest in four equal annual installments beginning on the firstanniversary of the RSU Grant Date. ( 10 )The transaction represents shares withheld by the Issuer in connection with the vesting of certain RSUs granted to the spouse of theReporting Person on the RSU Grant Date. These shares were withheld to satisfy the tax withholding obligations of the Reporting Person's spouse. The Issuer will pay these taxes on behalf of the Reporting Person's spouse.

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).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.