Arthur J. Gallagher & Co.: insurance broker profile

Overview

Arthur J. Gallagher & Co. is one of the four largest public brokers and, by its own filings, a serial acquirer. Its January 29, 2026 results release reported 2025 revenues before reimbursements of $13,778 million (total revenues, including reimbursements, were $13,942 million) and 71,776 employees at year-end, up from 55,977 a year earlier. The company says the AssuredPartners purchase added about 10,900 employees. J. Patrick Gallagher, Jr. is chairman and chief executive.

Gallagher has two reportable segments, according to its 2025 Form 10-K: Brokerage and Risk Management. Brokerage covers retail and wholesale broking, reinsurance broking and employee benefits consulting. Risk Management is Gallagher Bassett, a third-party claims administrator (see third-party administrator) that handles claims for self-insured employers and for insurers. The headquarters are at 2850 Golf Road, Rolling Meadows, Illinois.

History

The 10-K says the company was founded in 1927 and grew from a one-person insurance agency. It has since expanded mostly by purchasing other brokers, typically small and mid-sized agencies. The filing says individual acquisitions have typically ranged from $1 million to $100 million, and calls AssuredPartners "the largest acquisition in our history."

Earlier larger purchases listed in the January 2026 release include the treaty reinsurance brokerage operations of Willis Towers Watson, the benefits consultancy Buck, Cadence Insurance and Eastern Insurance Group, all of which closed in 2023.

Services

Gallagher's retail brokers place property, casualty, cyber, professional and specialty coverage for businesses, and its benefits teams advise on health plans, retirement and compensation. Wholesale operations place hard-to-place risks with surplus lines insurers (see wholesale brokers and surplus lines placement: how hard risks get insured and surplus lines broker), and the reinsurance business places reinsurance for insurers. Gallagher Bassett adjusts and administers workers' comp, liability and property claims. The 10-K also mentions its benefit consulting operations, which include Buck and Redington.

Who it serves

Gallagher's retail business centers on the U.S. middle market, with local offices that often keep their original agency names after an acquisition. The company says the AssuredPartners deal strengthened its capabilities in transportation, energy, healthcare, government contractors and public-entity business, and added operations in the United Kingdom and Ireland. Larger and multinational accounts are served as well. A small business will usually deal with a local Gallagher office rather than a central team; how a local agency differs from a global broker is covered in independent agent, broker, captive agent or direct? and how to choose a commercial insurance broker.

How it is paid

The 2025 Form 10-K describes commissions, fees, supplemental revenues and contingent revenues, and both of the last two come from insurers ("underwriting enterprises" in the filing's wording):

• Commissions and fees: the client pays a fee or the insurer pays a percentage of premium for placing and servicing coverage.
• Supplemental revenues: paid up front, annually or quarterly, generally based on historical premium volumes with the insurer and on additional capabilities or services Gallagher brings to the engagement.
• Contingent revenues: paid after the policy period, generally in the first or second quarter, based on the growth or profitability of the business Gallagher placed with that insurer in the prior year.

Because insurers pay supplemental and contingent amounts on top of commissions, a client can reasonably ask a broker for its written disclosure of all compensation on an account. how commercial insurance brokers get paid covers how these arrangements work across the industry.

Recent deals

• AssuredPartners: announced in December 2024 and completed on August 18, 2025. Trade press reported gross consideration of about $13.45 billion, financed by stock and notes sold in December 2024 and January 2025. Reported figures for the price vary slightly across sources, so we cite the figure from that coverage and the company's 10-K reference to its largest acquisition. AssuredPartners was a U.S. middle-market broker.
• Woodruff Sawyer: closed April 2025 (the results release and the 10-K list a context date of April 10, 2025).
• 2025 volume: the results release says Gallagher completed 33 mergers in 2025 that added more than $3.5 billion of estimated annualized revenue. The 10-K also lists Case Group, Tompkins Insurance Agencies, WK Webster and First Actuarial among 2025 acquisitions. We did not verify their closing dates.

For the industry-wide pattern, see private equity and the consolidation of insurance brokers.

Strengths and weaknesses

Gallagher gives a middle-market company a large, locally staffed network and a claims administrator under the same parent. Its steady purchases bring local relationships, though integration is demanding. Management said in January 2026 that it was integrating the AssuredPartners tuck-ins and that the work would continue through 2026.

• Strengths: a broad U.S. and international office network; benefits, wholesale, reinsurance and claims services in one group; deep acquisition experience.
• Weaknesses: the AssuredPartners integration is still under way; revenue from supplemental and contingent commissions calls for disclosure; acquired agencies may change systems and staff during integration.

How to contact Arthur J. Gallagher & Co.