Top insurance brokers, No. 3: Arthur J. Gallagher

2025 brokerage revenue: $13.17B
Percent increase: 18.9%

Arthur J. Gallagher & Co. spent the past year digesting the largest acquisition in its history, but CEO J. Patrick Gallagher Jr. says the company never lost momentum.

The brokerage completed its acquisition of AssuredPartners in August 2025, adding $3 billion in revenue and 11,000 employees. The company also completed the acquisition of San Francisco-based Woodruff Sawyer in April last year, and more than 30 smaller transactions.

In the first quarter, Gallagher reported a further nine acquisitions, including Bremen, Germany-based Krose GmbH & Co.

Gallagher reported 2025 brokerage revenue of $13.17 billion, up 18.9% over the prior year, retaining its position as the world’s third-largest brokerage. It reported 6% organic growth, with acquisitions contributing $3.5 billion in annualized revenue, Mr. Gallagher said. Gallagher also added staff, with nearly 72,000 staff in 2025 compared with about 56,000 in 2024.

The scale of the AssuredPartners transaction, which was the 10th-largest broker of U.S. business, raised questions about integration risk, but Mr. Gallagher said the transition has proceeded smoothly.

“We haven’t missed a step,” he said. “You could look at that and say, ‘What a risk.’ Our team and their team embraced the opportunity.”

AssuredPartners producers are using Gallagher’s investments in information technology, artificial intelligence and digitization, he said, and several AssuredPartners executives have senior management roles at Gallagher.

Gallagher’s culture remains a core feature that the company emphasizes with investors, said C. Gregory Peters, managing director, equity research, at Raymond James & Associates in Saint Petersburg, Florida. While publicly traded, the Gallagher family has invested significant energy in preserving what the company calls the Gallagher Way as the business has grown, he said.

Gallagher has maintained an entrepreneurial spirit among producers while institutionalizing back-office functions, supporting revenue growth, margin expansion and opportunistic mergers and acquisitions, Mr. Peters said.

Even with slower U.S. employment growth creating a headwind for exposures, Gallagher grew revenue and profit, he said.

The acquisition also strengthened Gallagher’s diversification, Mr. Gallagher said.

Gallagher has built significant operations in employee benefits, reinsurance and third-party claims administration through Gallagher Bassett, he said.

“We have a different mix than all of our major competitors,” Mr. Gallagher said. “We have both property casualty, a significant benefits operation, and we’ve got a multibillion-dollar operation in Gallagher Bassett.”

Gallagher Bassett is growing 10% organically, Mr. Gallagher said, and gives the company direct insight into claims, which  he described as central to the insurance business.

Gallagher’s market position extends beyond scale, said Steve Germundson, Eden Prairie, Minnesota-based partner at investment banking and financial consulting firm Optis Partners.

“I think Gallagher is very well positioned going forward,” he said. Businesses with deep industry expertise and strong client relationships should benefit from technology advances rather than be disrupted by them, he said.

Artificial intelligence is becoming another component of Gallagher’s growth strategy.

The company is already using AI to summarize claims, analyze client risk exposures and support producer and client-service functions, Mr. Gallagher said. It has moved beyond experimentation into scaled operational deployment, he said, citing 500,000 emails scanned, reviewed, categorized and indexed per month; 190,000 policies reviewed using AI; and 6,900 employees trained on Copilot.

Gallagher in May rolled out Blueprint, an AI-supported tool that analyzes middle-market clients’ risk profiles and shows how improvements could make them more attractive to insurers, he said.

“We are making ourselves a stronger player as an adviser,” Mr. Gallagher said.

Mr. Peters said AI-related concerns have weighed on brokers as investors assess potential disintermediation risk, but he sees the technology as more of a near-term opportunity for Gallagher. If software development and infrastructure costs decline, Gallagher also should benefit from an improved operational cost profile, he said.

Mr. Gallagher said AI will make Gallagher faster but will not replace its advisory role.

He acknowledged slower deal activity but said the company does not expect to pull back.

“We’ve got $10 billion of free cash flow to utilize over the next two years,” he said.