Marsh McLennan, which in January 2026 shortened its brand name to Marsh, is an insurance broker and consulting firm working with clients in 130 countries. As a broker it helps businesses, governments and individuals buy insurance and manage their risks, and it helps insurance companies buy reinsurance, which is insurance for insurers. Its consultants advise employers on employee health plans, retirement plans and pay, manage investments, and advise companies on strategy, brands and economics.
It has two segments. Risk and Insurance Services, made up of Marsh Risk and the reinsurance broker Guy Carpenter, brought in about 64% of revenue in 2025. It is paid mainly through commissions and fees, and also earns interest on client money it holds, such as premiums. Consulting, made up of Mercer and Marsh Management Consulting, which includes Oliver Wyman, Lippincott and NERA, brought in about 36%, from client fees, insurance commissions and fees based on assets it manages. Mercer managed about $692 billion in assets at the end of 2025. It competes with other insurance brokers, insurers that sell directly, banks, consulting firms and online platforms.
The company has annual revenue of about $27 billion and more than 95,000 employees. It grows partly by buying other firms, including McGriff Insurance Services, which it bought in November 2024 for $7.75 billion.