8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 19, 2026

Mistras Group, Inc.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (609) 716-4000

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2 below):

☐          Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐           Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐            Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d 2(b))

☐            Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Item 5.07. Submission of Matters to a Vote of Security Holders

Mistras Group, Inc. (the “Company”) held its 2026 annual shareholders meeting on May 19, 2026. Shareholders (1) elected the seven nominees to the Company’s Board of Directors for one-year terms, (2) ratified the appointment of PricewaterhouseCoopers LLP as the Company’s independent registered public accounting firm for 2026, (3) approved the Amendment to the MISTRAS Group, Inc., Amended and Restated 2016 Long-Term Incentive Plan; and (4) approved the Company’s executive compensation programs. These were the only matters voted upon at the meeting. The voting results are set forth below.

1. The seven nominees for election to the Board of Directors were elected based upon the following votes:

2. The appointment of PricewaterhouseCoopers LLP as the Company’s independent registered public accounting firm for 2026 was ratified based upon the following votes:

There were no broker non-votes for this item.

3. The approval of the Amendment to the MISTRAS Group, Inc. Amended and Restated 2016 Long-Term Incentive Plan was approved based on the following votes:

4. The advisory vote on the Company’s executive compensation was approved based upon the following votes:

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

3