Move over, RSM US, there’s about to be a new fifth-largest accounting firm in the U.S. based on revenue.
In huge M&A news today, Grant Thornton Advisors announced it will be acquiring CBIZ in an all-cash transaction with an enterprise value of $5 billion, backed by private equity firm New Mountain Capital, which has owned a majority stake in Grant Thornton since 2024.
The transaction is expected to close in the fourth quarter of 2026, subject to approval by CBIZ shareholders, regulatory clearances, and other customary closing conditions.
CBIZ is currently the only publicly traded accounting services provider (NYSE: CBZ) in the U.S.
This deal would be the largest of its kind in public accounting in more than 25 years. A series of deals between the Big Eight accounting firms in the late 1980s and 1990s formed the firms that are now the four largest in the U.S. today—Deloitte, PwC, Ernst & Young, and KPMG—with Coopers & Lybrand combining with Price Waterhouse to become PricewaterhouseCoopers in 1998 being the last such deal.
Upon closing, Chicago-based Grant Thornton is expected to have annual U.S. revenue of more than $5 billion, which would put the firm ahead of RSM US in fifth place behind the Big Four. According to the most recent rankings from INSIDE Public Accounting, eighth-place CBIZ and its audit and attest services affiliate, CBIZ CPAs, had combined revenue of $2.81 billion during its most recent financial year, while ninth-place Grant Thornton had revenue of $2.45 billion. RSM US had revenue of nearly $4.2 billion during its most recent fiscal year.
Grant Thornton sold a majority stake to New Mountain Capital in June 2024 and has since operated in an alternative practice structure: Grant Thornton LLP, a licensed CPA firm, provides attest services, and Grant Thornton Advisors LLC provides business advisory and non-attest services. According to a media release on Wednesday, New Mountain Capital will be investing incremental equity to support the acquisition of CBIZ.
Cleveland-based CBIZ made a huge announcement two years ago this week when it said it was acquiring then-top 15 accounting firm Marcum in a cash-and-stock transaction valued at approximately $2.3 billion. That deal vaulted CBIZ from 11th place in revenue to its current eighth-place position.
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As a result of the transaction with CBIZ, Grant Thornton Advisors will operate across more than 20 countries and territories, bring in close to $7.5 billion in annual global revenue, and have a workforce of more than 34,500 professionals across the Americas, Europe, the Middle East, and the Asia-Pacific region.
The transaction will also build on Grant Thornton Advisors’ $1 billion investment in artificial intelligence and advanced technologies, expanding the firm’s ability to bring AI-enabled solutions and capabilities to more clients and industries.
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“By combining our multinational platform with CBIZ’s strong market presence, we’re broadening our ability to support businesses through every stage of growth—from early development to global scale,” Grant Thornton Advisors CEO Jim Peko said in a statement on July 29. “Together, we’ll bring the quality, scope, and capabilities clients need to navigate an increasingly complex and rapidly evolving business environment.”
Under the terms of the definitive merger agreement, CBIZ shareholders will receive $55 in cash for each share of CBIZ common stock they own. This represents a premium of approximately 54% to CBIZ’s 30-day volume-weighted average share price, according to the media release. Reuters added that the offer price also represents a 17.8% premium over CBIZ’s most recent closing price.
Upon completion of the transaction, CBIZ will become wholly owned by Grant Thornton Advisors, and CBIZ stock will cease to trade and no longer be listed on the New York Stock Exchange.
The CBIZ Board of Directors has unanimously approved the transaction and recommended that CBIZ shareholders vote in favor of it.
“This is a historic combination with a complementary cultural and strategic fit. CBIZ has grown rapidly over many years to become a leading professional services provider. Joining Grant Thornton Advisors accelerates the realization of that vision, creating a stronger firm with new and exciting opportunities for our team members and enhanced service offerings for clients while delivering significant value to CBIZ shareholders,” Jerry Grisko, president and CEO of CBIZ, said in a statement.
Andre Moura, managing director of New Mountain Capital, added, “We’re pleased to continue to support Grant Thornton Advisors’ strategic growth plan, a journey we have been on together since May 2024. Following the acquisition of CBIZ, Grant Thornton in the U.S. will be the fifth-largest professional services, tax, and advisory provider in the nation and one of the most forward-thinking firms in the world regarding AI. That scale and forward momentum will put the combined firm in a stronger position than ever to serve its clients and create meaningful opportunities for its partners and staff.”
Following the closing, Grant Thornton Advisors plans to separate CBIZ’s Benefits and Insurance Services segment into a new stand-alone company backed by New Mountain Capital.
“We look forward to building on the strong foundations within the Benefits and Insurance Services segment to create a new leading firm dedicated to insurance, retirement, and payroll services—providing new opportunities to the clients and team members in that segment,” Bob Mulcare and Sean Donovan, managing directors at New Mountain Capital, said in a joint statement.
Under a go-shop provision, CBIZ can solicit alternative acquisition proposals through Aug. 27, 2026.
Goldman Sachs & Co. LLC is serving as financial advisor to CBIZ. Weil, Gotshal & Manges LLP is serving as legal advisor to CBIZ, and Teneo is serving as strategic communications advisor to CBIZ.
Deutsche Bank is acting as lead financial advisor for Grant Thornton Advisors. Other financial advisors include J.P. Morgan, BMO Capital Markets, BofA Securities, RBC Capital Markets, and UBS Investment Bank. Evercore is acting as financial advisor to New Mountain Capital and Grant Thornton on the CBIZ Benefits and Insurance segment. Simpson Thacher & Bartlett LLP, Mayer Brown LLP, and Hunton Andrews Kurth LLP are serving as legal advisors to Grant Thornton Advisors, and Goldin Solutions is serving as strategic communications advisor.
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