Marsh McLennan: insurance broker profile

Overview

Marsh McLennan is the largest publicly traded insurance broker and professional-services group in the world. It reported full-year 2025 revenue of $26,981 million, up 10% on a GAAP basis and 4% on an underlying basis from $24,458 million in 2024, in its results release of January 29, 2026. That release put its workforce at more than 95,000 people. John Doyle is president and chief executive.

The group changed its public brand in January 2026. It announced in October 2025 that it would be known simply as Marsh, and its New York Stock Exchange ticker moved to MRSH. Legal filings still use the name Marsh & McLennan Companies, Inc., and this profile uses the name most business buyers still search for.

Four businesses sit under the holding company, per its 2024 annual report and the January 2026 release: Marsh (the retail broker, labeled Marsh Risk in the results release), Guy Carpenter (reinsurance broking), Mercer (consulting, health and retirement) and Oliver Wyman (management consulting, with its operating unit renamed Marsh Management Consulting). For most U.S. business buyers the relevant pieces are Marsh itself, for large and complex accounts, and Marsh McLennan Agency (MMA), for small and mid-sized ones.

History

The 2024 10-K traces Marsh to 1871. The company credits itself with early work in representing clients rather than insurers, and in building risk management as a discipline for corporate buyers. Over the following century and a half it grew into a group that combines broking with actuarial, benefits and strategy consulting.

The most recent step-change came in 2024. Marsh McLennan closed its purchase of McGriff Insurance Services on November 15, 2024, for $7.75 billion in cash, according to its 2024 10-K and trade coverage. Trade press described McGriff as a U.S. broker with about $1.3 billion of annual revenue. McGriff's staff of more than 3,500 joined MMA. The company financed the deal partly with $7.25 billion of senior notes. The January 2026 results release says the McGriff integration was completed in 2025.

Services

Marsh places property, casualty, cyber, financial and professional lines, and advises on total cost of risk, captives and retention strategy. Guy Carpenter brokers reinsurance for insurers. That matters to a business owner indirectly, because the reinsurance market sets part of the capacity and price behind commercial policies (see how reinsurance pricing flows into business insurance premiums). Mercer handles employee benefits consulting, retirement and investments. MMA offers property and casualty brokerage and employee benefits to small and mid-sized employers.

The group also publishes market data. Its Global Insurance Market Index, for example, reported U.S. cyber rates down 2% in the second quarter of 2026.

Who it serves

Marsh serves multinationals, large public companies, governments and public-sector entities, and companies with captive insurers. MMA targets the middle market and smaller businesses, usually through local offices that came from earlier acquisitions. A company with a few dozen employees and a single location is far more likely to meet an MMA office than the global Marsh team. Reinsurance clients are insurers, not businesses buying cover.

If you are weighing a global firm against a local agency, how to choose a commercial insurance broker and independent agent, broker, captive agent or direct? explain the differences, and a Writing a broker RFP for a commercial insurance program is the usual way to compare them.

How it is paid

Marsh's 2024 10-K says Marsh and Guy Carpenter are paid for brokerage and consulting through commissions and fees, with rates that vary by type of coverage, by insurer or reinsurer, and by the capacity in which the broker acts. The firm also receives other compensation from insurers: payments for consulting and analytics, fees for administrative services, and contingent commissions, which the filing describes as paid "by insurers based on factors such as volume or profitability of Marsh's placements." The filing says those contingent commissions come primarily from MMA and parts of Marsh's international operations.

Large programs are often priced as a negotiated fee in place of commission, while smaller accounts commonly pay commission built into the premium. Ask for the compensation disclosure in writing before you sign a broker-of-record letter. The general mechanics are in how commercial insurance brokers get paid.

Recent deals

• McGriff Insurance Services: closed November 15, 2024; $7.75 billion in cash; folded into MMA.
• Rebrand: announced October 2025; effective January 2026, with a ticker change to MRSH. Press coverage of the announcement said the businesses would adopt the Marsh name from 2027, after a transition period, and that a business and client services unit would combine technology, data and operations teams.

Marsh also buys smaller agencies regularly through MMA. We did not verify individual tuck-in deals for 2025 and 2026 and do not list them here. For the wider pattern, see private equity and the consolidation of insurance brokers.

Strengths and weaknesses

Scale is the draw. Marsh has global placement capability, reinsurance and benefits consulting in the same group, and market pricing data that few firms match. A risk manager gets analytics and board-level reporting from one relationship.

The weaknesses are the usual ones for a very large broker. A mid-sized company can be one of many clients, and the group's consulting and broking businesses can create potential conflicts, which is why compensation disclosure matters. Contingent commissions from insurers are a reason to ask how placement decisions are made.

• Strengths: global reach and market access; a large middle-market network through MMA; reinsurance and benefits consulting under one group.
• Weaknesses: size can mean less attention for smaller accounts; insurer-paid compensation needs explanation; the 2026 and 2027 brand transition may blur which entity you are dealing with.

How to contact Marsh McLennan