In a move poised to redraw the map of the professional services industry, Grant Thornton To Buy CBIZ has become one of the year's biggest corporate acquisitions. Backed by New Mountain Capital, Grant Thornton Advisors announced Wednesday that it has reached an agreement to acquire CBIZ Inc. in an all-cash transaction valued at approximately $5 billion, including debt.

The acquisition positions Grant Thornton to emerge as the fifth-largest provider of professional, tax, and advisory services in the United States, signaling a dramatic expansion in both scale and market reach.

Legal counsel is spread among several major law firms. Simpson Thacher & Bartlett LLP, Mayer Brown LLP, and Hunton Andrews Kurth LLP are advising Grant Thornton, while Weil Gotshal & Manges LLP represents CBIZ throughout the transaction.

Shareholders Receive Premium Cash Offer

Under the terms of the agreement, CBIZ shareholders will receive $55 in cash for every share of common stock they own.

Investors reacted quickly after the announcement. CBIZ shares surged more than 16% during Wednesday morning trading, climbing to approximately $54.39 per share, reflecting market confidence that the transaction is likely to move forward.

Once the acquisition is finalized, CBIZ will become a wholly owned subsidiary of Grant Thornton Advisors, and its common stock will be removed from trading on the New York Stock Exchange.

A Global Expansion Fueled by Technology

Like two powerful rivers merging into one stronger current, the combination of Grant Thornton and CBIZ is expected to significantly increase the firm's capabilities.

Grant Thornton projects that its U.S. operations will generate more than $5 billion in annual domestic revenue following the merger. On a global scale, the combined organization is expected to operate across more than 20 countries and territories, producing nearly $7.5 billion in annual revenue while employing over 34,500 professionals.

The acquisition also supports Grant Thornton's broader strategy of investing $1 billion in artificial intelligence and advanced technologies, reinforcing its commitment to digital transformation.

CEO Highlights Growth Strategy

Grant Thornton Chief Executive Officer Jim Peko said the acquisition strengthens the firm's ability to serve businesses at every phase of development.

He said combining Grant Thornton's international platform with CBIZ's established market presence will expand the company's capacity to help organizations grow from early-stage operations into global enterprises.

CBIZ Leadership Sees Long-Term Value

CBIZ President and CEO Jerry Grisko described the merger as a significant opportunity for employees, clients, and shareholders alike.

According to Grisko, joining Grant Thornton will create a stronger organization with expanded service offerings, fresh career opportunities for employees, and meaningful value for shareholders through the cash transaction.

New Mountain Capital Deepens Investment

Private equity firm New Mountain Capital, headquartered in New York, continues to play a central role in Grant Thornton's growth strategy.

The investment firm, which oversees approximately $60 billion in assets under management, previously led a strategic investment in Grant Thornton in May 2024. It will now provide additional equity financing to help complete the CBIZ acquisition.

Following the transaction's completion, Grant Thornton intends to separate CBIZ's benefits and insurance services division into a newly formed independent company that will also receive backing from New Mountain Capital.

Regulatory Review and Closing Timeline

The CBIZ board of directors has unanimously approved the acquisition agreement.

The transaction is expected to close during the fourth quarter of 2026, pending approval from CBIZ shareholders as well as required regulatory clearances.

The agreement also includes a go-shop period that will remain open until Aug. 27, allowing CBIZ to consider alternative proposals before the exclusivity period concludes.

Legal Teams Steering the Transaction

The legal work behind the multibillion-dollar acquisition involves several prominent firms.

The Simpson Thacher & Bartlett LLP team is led by partner Ben Schaye, while Weil Gotshal & Manges LLP is led by partner Michael J. Aiello.

At Mayer Brown LLP, the advisory team includes partners Paul Theiss, Camila Panama, and Brian Hirshberg.

Details regarding the legal team representing Hunton Andrews Kurth LLP were not immediately available following the announcement.