Grant Thornton Seals Accounting Sector's Largest Takeover in a Generation with $5 Billion CBIZ Deal

 Grant Thornton Seals Accounting Sector's Largest Takeover in a Generation with $5 Billion CBIZ Deal

**The all-cash acquisition of CBIZ reshapes the mid-tier landscape, creating the fifth-largest U.S. professional services firm and signaling a new era of AI-driven consolidation.**

---

## A Historic Deal That Changes the Game

On July 28, 2026, Grant Thornton Advisors announced a definitive agreement to acquire CBIZ, Inc. in an all-cash transaction valued at $5 billion. The deal represents the largest of its kind in more than 25 years and will create the fifth-largest provider of professional services, tax, and advisory services in the United States .

Under the terms of the agreement, CBIZ shareholders will receive **$55.00 per share in cash**. That's a premium of approximately **54%** to CBIZ's 30-day volume-weighted average price and about **17.8%** above its most recent closing price . The offer sent CBIZ shares soaring roughly 17% in morning trading, marking the stock's largest single-day gain in over 20 years .

Upon closing, Grant Thornton in the U.S. will have more than $5 billion in annual domestic revenue. The combined multinational platform will span **more than 20 countries and territories**, generate nearly **$7.5 billion in revenue**, and employ **more than 34,500 professionals** across the Americas, Europe, the Middle East, and Asia-Pacific .

"This is a historic combination with a complementary cultural and strategic fit," said Jerry Grisko, president and CEO of CBIZ. "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" .

## Why This Deal Matters: The Big Four Challenger

The acquisition is a direct challenge to the dominance of the Big Four accounting firms—Deloitte, EY, KPMG, and PwC—which have long towered over the U.S. accounting industry . Before the deal, Grant Thornton and CBIZ ranked among the largest firms outside the Big Four. Together, they are betting that scale, technology, and global reach can close the gap .

Grant Thornton Advisors CEO Jim Peko framed the deal as part of a larger vision: "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" .

The deal reflects a broader consolidation trend in the accounting sector, where mid-market firms are joining forces to compete with larger global players . In 2025, Baker Tilly and Moss Adams combined in a $7 billion deal. CBIZ itself had already expanded rapidly through acquisitions, including its $2.3 billion purchase of accounting firm Marcum in 2024 .

## The AI Factor: A $1 Billion Technology Bet

Grant Thornton's $5 billion bet on CBIZ isn't just about size—it's about technology. The acquisition builds on Grant Thornton's recently announced **$1 billion investment in AI and advanced technologies** . The combined firm plans to accelerate AI-enabled service delivery, using artificial intelligence to transform client service, empower employees, and unlock new growth opportunities .

New Mountain Capital, which led a May 2024 investment in Grant Thornton and fueled its growth strategy, is making an additional equity investment to support the deal . Andre Moura, managing director of New Mountain Capital, said the acquisition positions Grant Thornton as "one of the most forward-thinking firms in the world regarding AI" .

## What Happens to CBIZ's Benefits and Insurance Business?

After the deal closes, Grant Thornton plans to separate CBIZ's Benefits and Insurance Services segment into a new stand-alone entity backed by New Mountain Capital . This carve-out is designed to let the insurance, retirement, and payroll services business grow independently while Grant Thornton focuses on its core professional services, tax, and advisory offerings .

## When Will the Deal Close?

The transaction is expected to close in the **fourth quarter of 2026**, subject to CBIZ shareholder approval, regulatory clearances, and other customary conditions . The CBIZ board has unanimously approved the deal and recommends shareholders vote in favor .

There's a **"go-shop" provision** that allows CBIZ to solicit alternative acquisition proposals through **August 27, 2026** . If a superior offer emerges, CBIZ can terminate the merger agreement, subject to certain conditions and a termination fee .

## What This Means for Clients and Employees

For clients, the combined firm promises broader cross-border support, enhanced advisory services, deeper industry specialization, and AI-powered technology solutions . For employees, the deal creates new opportunities for growth and career development at a firm that now ranks among the top five in the U.S. .

Grant Thornton emphasized that it will maintain a strong focus on quality, trust, and client service—a commitment that has been central to its brand .

---

## Disclaimer

**IMPORTANT:** This article is for informational purposes only and does not constitute financial, investment, or professional advice. The information contained herein is based on publicly available sources and reflects the author's understanding as of the publication date. M&A transactions, corporate strategies, and market conditions are subject to change. You should consult with qualified professionals for guidance on specific issues.

---

*Published: July 29, 2026*

-Read more--

**Tags:** Grant Thornton, CBIZ, accounting, M&A, professional services, Big Four, consolidation, AI in accounting, New Mountain Capital, tax and advisory, $5 billion deal, industry consolidation