Sec Form 3 Filing - Sotirios Vahaviolos January 2023 2-Year Grantor Retained Annuity Trust @ Mistras Group, Inc. - 2023-01-09

FORM 3 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 Sotirios Vahaviolos January 2023 2-Year Grantor Retained Annuity Trust 2. Issuer Name and Ticker or Trading Symbol Mistras Group, Inc. [ MG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O MISTRAS GROUP, 195 CLARKSVILLE ROAD 3. Date of Earliest Transaction (MM/DD/YY) 01/09/2023 (Street) PRINCETON JUNCTION, NJ08550 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 6,734,718 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

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Sotirios Vahaviolos January 2023 2-Year Grantor Retained Annuity Trust C/O MISTRAS GROUP 195 CLARKSVILLE RO AD PRINCETON JUNCTION, NJ08550 X Signatures /s/ Michael C. Keefe, attorney-in-fact for Stephanie Foglia, Trustee 01/20/2023 Signature of Reporting Person Date

Explanation of Responses:

Remarks: Reporting person was established by the grantor, Sotirios Vahaviolos, Executive Chairman and Founder of the Issuer. The shares were acquired a gift by Dr. Vahaviolos. Dr. Vahaviolos' daughter, who does not reside with him, is the trustee for the the trust and will hold sole power over the voting and disposition of the shares of Mistras Group common stock held by the trust. Dr. Vahaviolos and the GRAT trustee have agreed that the GRAT will be subject to the issuer's insider trading compliance policy regarding the shares of Mistras Group common stock held by the trust.

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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