Marsh & McLennan is a global professional services company that helps organizations and individuals manage risk, navigate insurance, and make strategic business decisions across 130 countries. Its Risk and Insurance Services segment (two-thirds of revenue) operates through Marsh Risk, a leading insurance broker serving businesses and individuals with risk management and insurance broking services, and Guy Carpenter, a reinsurance intermediary providing treaty broking, advisory, and capital solutions. Its Consulting segment (one-third of revenue) comprises Mercer, which offers health, wealth, and career advisory services including retirement plan consulting and health benefits outsourcing, and Marsh Management Consulting, which includes Oliver Wyman (transformation and strategy consulting), Lippincott (brand strategy), and NERA (economic consulting). The company earns revenue through insurance commissions and fees, reinsurance placement commissions, professional consulting fees, and asset-based compensation from wealth management services.