Mistras Group to Be Acquired by H.I.G. Capital for $20.35 a Share

What happened

Mistras Group, Inc. (NYSE: MG) said on September 17, 2026 that it entered into an Agreement and Plan of Merger with Athena Purchaser, LLC and its subsidiary Athena Merger Sub, Inc., according to a Form 8-K filed September 18. Parent and Acquisition Sub are controlled by funds affiliated with H.I.G. Capital.

Under the merger, Acquisition Sub will merge into Mistras, and Mistras will survive as a wholly owned subsidiary of Parent. Each outstanding share of Mistras common stock will be converted into the right to receive $20.35 in cash, without interest, except for treasury shares, shares held by Parent or Acquisition Sub, and shares held by stockholders who properly exercise and do not withdraw appraisal rights under Delaware law.

Mistras shares closed at $20.75 on September 18, up 4.59% from the prior close of $19.84, on volume of 2.56 million shares against a 237,935-share average, according to the price data. The filing does not explain the price move.

The Mistras board unanimously determined the merger is fair to and in the best interests of the company and its stockholders, approved it, and recommended that stockholders adopt the merger agreement. Completion requires adoption by holders of a majority of outstanding shares, among other conditions.

The go-shop, the breakup fees, and the vote

The merger agreement includes a 40-day "go-shop" period beginning on the date of the agreement, during which Mistras may solicit alternative acquisition proposals and negotiate with third parties. After that period ends, the company is generally barred from soliciting or negotiating alternative proposals, subject to customary exceptions.

Either party may terminate under specified circumstances. If Mistras terminates to sign a superior proposal, it owes Parent a termination fee of approximately $27.5 million; if the termination relates to a superior proposal made during the go-shop period, the fee is halved to 50% of that amount, or roughly $13.75 million. Parent pays Mistras a $49.9 million termination fee in certain circumstances, including a willful and material breach by Parent or a failure to close when required. Parent can also obtain up to $7.0 million in expense reimbursement from Mistras if Parent terminates over Mistras's willful and material breach.

Concurrently with the merger agreement, each Mistras director and named executive officer and certain other stockholders entered voting and support agreements with Parent. Those shares cover approximately 31% of Mistras's issued and outstanding common stock. Under the agreements, those holders agreed to vote in favor of adopting the merger agreement and against competing acquisition proposals.

The merger is not subject to a financing condition. Parent obtained an equity commitment letter from H.I.G. Middle Market LBO Fund IV, L.P. and a debt commitment letter from certain financial institutions. H.I.G. Middle Market LBO Fund IV, L.P. also delivered a limited guarantee for certain Parent obligations, including the Parent Termination Fee.

Executive retention bonuses and the Form 8-K items

On September 17, 2026, in connection with the contemplated merger, the Compensation Committee of the Mistras board approved cash retention bonus awards for key employees, including President and CEO Natalia Shuman ($750,000), Senior Executive Vice President and CFO Edward J. Prajzner ($425,000), Executive Vice President and Chief Commercial Officer Gennaro D'Alterio ($245,000), and Executive Vice President and Chief Operating Officer Hani Hammad ($425,000).

Each award vests 50% at the effective time of the merger and 50% on the 12-month anniversary of the effective time, subject to continued employment through the applicable vesting date. If a recipient's employment is terminated after the effective time without cause or due to resignation for good reason, the unvested portion vests in full, subject to a timely general release of claims. The agreements will be memorialized in retention bonus letter agreements, a form of which will be filed with Mistras's Form 10-Q for the quarter ending September 30, 2026.

The 8-K checked Item 1.01 (entry into a material definitive agreement), Item 5.02 (officer compensation arrangements), Item 7.01 (Regulation FD disclosure), Item 8.01 (other events), and Item 9.01 (exhibits). Under Item 7.01, Mistras and Parent issued a joint press release announcing the merger agreement, attached as Exhibit 99.1. That exhibit is furnished to the SEC rather than filed, meaning it is not subject to Section 18 liability or automatically incorporated into other filings.

What this means

Mistras Group is an engineering services company providing asset protection and inspection services such as non-destructive testing, headquartered in Princeton Junction, New Jersey.

The Form 8-K is a current report that public companies must file with the SEC when certain material events occur, generally within four business days. Rather than an annual or quarterly report, it is a one-off disclosure of a specific event. The item numbers on the form indicate what kind of event is being reported; this filing combines five items in one document because a single transaction produced a merger agreement, executive compensation changes, a press release, voting agreements, and exhibits.

A merger agreement is the contract setting the price and terms for an acquisition. Here, the buyer is a private equity firm, H.I.G. Capital, which is acquiring Mistras through a shell entity and its subsidiary. A merger such as this means the company's stock stops trading on the New York Stock Exchange and the company becomes privately held once the deal closes.

The $20.35 per share cash price is the amount each holder of Mistras common stock would be paid at closing, other than shares excluded in the agreement or held by stockholders who pursue appraisal rights. Appraisal rights are a Delaware legal procedure letting stockholders who object to a merger ask a court to determine the fair value of their shares instead of accepting the merger price.

The go-shop period is a set number of days after signing during which the target company may actively look for a higher bid. A termination fee is the amount one party pays the other if the deal is called off under specified conditions; it compensates the buyer for the work and risk of a transaction that does not close.

Voting agreements are contracts in which stockholders agree in advance to vote their shares a certain way. Because they cover roughly 31% of the shares, they give the buyer more certainty that the majority vote needed to adopt the merger agreement will be reached, though the filing states the vote is still required.

Completion of the merger is not guaranteed. It requires, among other conditions, the majority stockholder vote, expiration or termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act and other regulatory approvals, and the absence of any order or law blocking the merger. The filing lists these conditions without stating a closing date.