Sec Form 4 Filing - Walbert Timothy P @ Horizon Therapeutics Public Ltd Co - 2023-01-04

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 Walbert Timothy P 2. Issuer Name and Ticker or Trading Symbol Horizon Therapeutics Public Ltd Co [ HZNP] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chairman, President and CEO (Last) (First) (Middle) C/O HORIZON THERAPEUTICS PLC,, 70 ST. STEPHEN?S GREEN 3. Date of Earliest Transaction (MM/DD/YY) 01/04/2023 (Street) DUBLIN, L2D02 E2X4 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 Ordinary Shares 01/05/2023 M 219,995 A 713,954 D Ordinary Shares 01/05/2023 F 97,461 D $ 113.24 616,493 D Ordinary Shares 107,739 I See Footnote( 2 ) Ordinary Shares 100,300 I See Footnote( 3 ) Ordinary Shares 49,656 I By Spouse

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 (RSUs) ( 1 ) 01/04/2023 A 71,290 ( 4 ) ( 4 ) Ordinary Shares 71,290 $ 0 71,290 D Restricted Stock Units (RSUs) ( 1 ) 01/04/2023 A 20,697 ( 4 ) ( 4 ) Ordinary Shares 20,697 $ 0 20,697 I By Spouse Restricted Stock Units (RSUs) ( 1 ) 01/05/2023 M 58,055 ( 5 ) ( 5 ) Ordinary Shares 58,055 $ 0 0 D Restricted Stock Units (RSUs) ( 1 ) 01/05/2023 M 34,928 ( 6 ) ( 6 ) Ordinary Shares 34,928 $ 0 34,929 D Restricted Stock Units (RSUs) ( 1 ) 01/05/2023 M 24,598 ( 7 ) ( 7 ) Ordinary Shares 24,598 $ 0 49,198 D Performance Restricted Stock Units (PSUs) ( 1 ) 01/05/2023 M 34,835 ( 8 ) ( 8 ) Ordinary Shares 34,835 $ 0 0 D Performance Restricted Stock Units (PSUs) ( 1 ) 01/05/2023 M 9,435 ( 8 ) ( 8 ) Ordinary Shares 9,435 $ 0 0 D Performance Restricted Stock Units (PSUs) ( 1 ) 01/05/2023 M 23,200 ( 8 ) ( 8 ) Ordinary Shares 23,200 $ 0 0 D Performance Restricted Stock Units (PSUs) ( 1 ) 01/05/2023 M 39,944 ( 6 ) ( 6 ) Ordinary Shares 39,944 $ 0 17,448 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Walbert Timothy P C/O HORIZON THERAPEUTICS PLC, 70 ST. STEPHEN?S GREEN DUBLIN, L2D02 E2X4 X Chairman, President and CEO Signatures /s/ Adriana Hernandez-Capone, Attorney-in-Fact 01/06/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Each PSU/RSU represents a contingent right to receive one ordinary share of the Issuer. ( 2 )The shares are held by the Timothy P. Walbert 2021 Gift Trust, of which the Reporting Person's spouse is the Trustee and beneficiary. ( 3 )The shares are held by the Keli B. Walbert 2021 Gift Trust, of which the Reporting Person is the Trustee. The beneficiaries of the Trust include the Reporting Person and his descendants. ( 4 )The RSUs vest 1/3rd annually on each anniversary of January 5, 2023. ( 5 )The final tranche of ordinary shares subject to the RSU vested on January 5, 2023. ( 6 )The remaining ordinary shares subject to the PSU/RSU vest on January 5, 2024. ( 7 )The remaining ordinary shares subject to the RSU vest ratably on January 5, 2024 and January 5, 2025. ( 8 )The ordinary shares subject to the PSU vested on January 5, 2023.

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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