Sec Form 4 Filing - HORNBUCKLE WILLIAM @ MGM Resorts International - 2023-08-18

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 HORNBUCKLE WILLIAM 2. Issuer Name and Ticker or Trading Symbol MGM Resorts International [ MGM] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) CEO AND PRESIDENT (Last) (First) (Middle) 3600 LAS VEGAS BLVD., S. 3. Date of Earliest Transaction (MM/DD/YY) 08/18/2023 (Street) LAS VEGAS, NV89109 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 $.01 Par Value ND ( 1 ) 08/18/2023 A 153,996 A $ 0 220,223 D Common Stock $.01 Par Value ND 08/18/2023 F 60,598 D $ 42.54 159,625 D Common Stock $.01 Par Value ND ( 2 ) 08/18/2023 A 143,768 A $ 0 303,393 D Common Stock $.01 Par Value ND 08/18/2023 F 56,573 D $ 42.54 246,820 D Common Stock $.01 Par Value ND 08/18/2023 M 38,212 A $ 0 285,032 D Common Stock $.01 Par Value ND 08/18/2023 F 15,038 D $ 42.54 269,994 D Common Stock $.01 Par Value ND 172,781 I In trust

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 ( 3 ) 08/18/2023 M 38,212 08/18/2021 08/18/2024 Common Stock $.01 Par Value ND 38,212 $ 0 38,213 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other HORNBUCKLE WILLIAM 3600 LAS VEGAS BLVD., S. LAS VEGAS, NV89109 X CEO AND PRESIDENT Signatures /s/ Jessica Cunningham, Attorney-In-Fact 08/22/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents the vesting of 96,247.91563 performance share units (PSUs) granted on August 18, 2020 under the MGM Resorts International (Company) Amended and Restated 2005 Omnibus Incentive Plan (Plan). Each PSU represented the right to receive between 0 and 1.6 shares of Company common stock depending upon the performance of the common stock from the grant date to the date that was three years after the grant date (Vesting Date), relative to a target price of $21.85 (Target Price). The Target Price is equal to 125% of the average closing price of Company common stock over the 60-calendar day period ending on the grant date. The number of shares issued per PSU, 1.6 shares, was calculated by dividing the ending average stock price by the Target Price. For this purpose, the ending average stock price is the average closing price of Company common stock over the 60-day period ending on the Vesting Date, as adjusted to include dividends paid during the term of the PSU. ( 2 )Represents the vesting of 95,845.62759 PSUs granted on August 18, 2020, under the Plan. The number of shares awarded at the end of the performance period was based upon the Company's three-year total shareholder return (TSR) compared to the TSRs of the constituents of the S&P 500 Index. ( 3 )Restricted Stock Units ("RSUs") granted under the Plan. Each RSU represents the right to receive, following vesting, one share of Company common stock. Any fractional shares are paid in cash upon settlement.

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).

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