# EDGAR Filing Document

**Accession Number:** 0001436126
**File Stem:** 0002082289-26-000006
**Filing Date:** 2026-6
**Character Count:** 4840
**Document Hash:** 928dbff9ece4141967b743c04bce00d9
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0002082289-26-000006.hdr.sgml**: 20260604

**ACCESSION NUMBER**: 0002082289-26-000006

**CONFORMED SUBMISSION TYPE**: 3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20251231

**FILED AS OF DATE**: 20260604

**DATE AS OF CHANGE**: 20260604

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Foglia Stephanie Athena
- **CENTRAL INDEX KEY:** 0002082289

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-34481
- **FILM NUMBER:** 261064916

**MAIL ADDRESS:**
- **STREET 1:** 504 HIRAM ROAD
- **CITY:** PLYMOUTH MEETING
- **STATE:** PA
- **ZIP:** 19462
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Mistras Group, Inc.
- **CENTRAL INDEX KEY:** 0001436126
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-ENGINEERING SERVICES [8711]
- **ORGANIZATION NAME:** 07 Trade & Services
- **EIN:** 223341267
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 195 CLARKSVILLE ROAD
- **CITY:** PRINCETON JUNCTION
- **STATE:** NJ
- **ZIP:** 08550
- **BUSINESS PHONE:** 609-716-4000

**MAIL ADDRESS:**
- **STREET 1:** 195 CLARKSVILLE ROAD
- **CITY:** PRINCETON JUNCTION
- **STATE:** NJ
- **ZIP:** 08550

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 3

### INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Foglia Stephanie Athena<br><sub>(Last) (First) (Middle)</sub><br>195 CLARKKSVILLE ROAD<br><sub>(Street)</sub><br>PRINCETON JUNCTION, NJ 08550<br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>Mistras Group, Inc. [ MG ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2025-12-31 | **4. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director   [X] 10% Owner<br>[ ] Officer (give title below)   [ ] Other (specify below)<br>_ _ | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities Beneficially Owned

---

|  |  |  |  |
| --- | --- | --- | --- |
| 1. Title of Security | 2. Amount of Securities Beneficially Owned | 3. Ownership Form | 4. Nature of Indirect Beneficial Ownership |
| Common Stock | 1393324 | D |  |
| Common Stock | 5692 | I | By Spouse |
| Common Stock | 15366 | I | By Child |
| Common Stock | 52547 | I | By GRAT |
| Common Stock | 20106 | I | By Child |
| Common Stock | 52547 | I | By GRAT |
| Common Stock | 19005 | I | By Child |
| Common Stock | 54008 | I | By GRAT |
| Common Stock | 5251358 | I | By GRAT<sup>(1)</sup> |

---

## Table II - Derivative Securities Beneficially Owned

---

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 3. Title and Amount of Underlying Securities | 3. Title and Amount of Underlying Securities | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) The reporting person is the trustee for the 2025 Irrevocable Two-Year Grantor Retained Annuity Trust of Aspasia F. Vahaviolos ("GRAT") and holds sole power over the voting and disposition of the issuer's common stock held by the GRAT. The reporting person disclaims beneficial ownership of these shares except to the extent of her pecuniary interest therein.

**Signature:** /s/ Stephanie Athena Foglia  
**Date:** 2026-06-04

### Remarks:

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.**