CBIZ, Inc. (CBZ) shares jumped 17.67% to $54.95 after Grant Thornton Advisors announced a $5 billion all-cash acquisition. The deal values each CBIZ share at $55, representing a significant premium over recent trading levels. Upon closing, the combination would form the fifth-largest professional services provider in the United States, breaking into a tier long dominated by Deloitte, PwC, EY, and KPMG.

Grant Thornton Sets $55 Cash Offer

Grant Thornton Advisors has agreed to acquire CBIZ in a transaction valued at $5 billion. Under the agreement terms, CBIZ shareholders will receive $55 in cash for each common share they own — approximately a 54% premium to CBIZ's 30-day volume-weighted average share price.

New Mountain Capital will provide additional equity for the transaction. The private equity firm has supported Grant Thornton's growth strategy since May 2024, when it led an investment that helped expand the firm's U.S. operations. That backing reflected a broader trend of private capital flowing into the accounting and advisory sector, where firms have sought outside investment to fund technology builds and pursue acquisitions. The new funding will support both the purchase and the combined company's broader growth plans.

CBIZ's board unanimously approved the agreement and recommended shareholder support. The companies expect to complete the acquisition during the fourth quarter of 2026, pending shareholder approval, regulatory clearance, and other customary closing conditions.

Combined Firm Targets Greater Scale

The merger would create a U.S. business generating more than $5 billion in annual domestic revenue, ranking as the country's fifth-largest provider of professional, tax, and advisory services. The transaction represents the industry's largest combination in more than 25 years — a span during which large-firm consolidation has been relatively rare, partly because of partnership structures and regulatory scrutiny.

On a multinational level, the combined platform would operate across more than 20 countries and territories, generating nearly $7.5 billion in revenue and employing over 34,500 professionals worldwide. Grant Thornton expects the expanded network to strengthen cross-border service capabilities and broaden specialist offerings.

Grant Thornton also intends to extend its technology platform across CBIZ's client base. The firm recently announced a $1 billion investment in artificial intelligence and advanced technology, which the combined business expects will improve service delivery, staff productivity, and client support.

Benefits Unit Faces Separate Future

Following the acquisition's completion, Grant Thornton plans to separate CBIZ's Benefits and Insurance Services segment into a new independent company backed by New Mountain Capital. The standalone business would focus on insurance, retirement, payroll, and related services for existing clients.

Under the merger agreement, CBIZ may solicit alternative acquisition proposals during a go-shop period ending August 27, 2026. The company's advisers can review and negotiate competing bids during that window, and the board may accept a superior proposal if one materializes under the agreement's stated conditions.

Once the transaction closes, Grant Thornton will own CBIZ outright. CBIZ shares will cease trading and be delisted from the New York Stock Exchange. Until then, the company will continue operating under its current structure and public listing. The modest gap between CBIZ's closing price of $54.95 and the $55 offer price reflected typical deal-completion uncertainty, including the long runway to a projected Q4 2026 close.