A new top 5 firm: Grant Thornton acquiring fellow top 10 firm CBIZ

Top 10 accounting firm Grant Thornton is acquiring fellow top 10 firm CBIZ to form a firm that’s outsized only by the Big Four in terms of U.S. revenue.

The transaction, expected to close in the fourth quarter of 2026 according to a news release, will result in Grant Thornton Advisors acquiring CBIZ in an all-cash transaction. The merged firm is expected to become the fifth-largest U.S. provider of professional services, tax, and advisory services, with more than $5 billion in annual domestic revenue, the release said.

The transaction is the largest of its kind in more than 25 years, the news release said. In 1998, PwC was formed by the merger of Coopers & Lybrand and Price Waterhouse.

Private-equity investment company New Mountain Capital, which made a “significant growth investment” in Grant Thorton in 2024, is investing incremental equity to support the CBIZ transaction. Following completion of the transaction, Grant Thornton Advisors plans to separate CBIZ’s Benefits and Insurance Services segment into a new standalone entity backed by New Mountain Capital, the release said.

Jim Peko, CEO of Grant Thornton Advisors LLC and leader of the Grant Thornton Advisors multinational platform, said in the release: “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. Together, we’ll bring the quality, scope, and capabilities clients need to navigate an increasingly complex and rapidly evolving business environment.”

When the deal closes, the new firm will have more than 34,500 employees in more than 20 countries and territories and more than $7.5 billion in global revenue.

 “This is a historic combination with a complementary cultural and strategic fit,” Jerry Grisko, CEO of publicly traded CBIZ, said in the release.  “CBIZ has grown rapidly over many years to become a leading professional services provider. Joining Grant Thornton Advisors accelerates the realization of that vision. …”

Terms of the agreement stipulate that CBIZ shareholders will receive $55 per share in cash, representing a premium of about 54% to CBIZ’s 30-day volume-weighted average share price, the release said. When the transaction is completed, CBIZ will become wholly owned by Grant Thornton Advisors, and CBIZ common stock will cease to trade and will no longer be listed on the New York Stock Exchange.

In 2024, CBIZ moved into the top 10 by acquiring fellow top 15 firm Marcum.

— To comment on this article or to suggest an idea for another article, contact Bryan Strickland at Bryan.Strickland@aicpa-cima.com.