The undisputed number one insurance broker in the United States and globally by total annual revenue is Marsh & McLennan Companies (Marsh). Operating through specialized subsidiaries—including Marsh for commercial insurance broking and risk management, Guy Carpenter for reinsurance advisory, and Mercer for human resources and employee benefits consulting—the firm commands a leading position in the commercial insurance marketplace. It manages complex risk portfolios for Fortune 500 corporations, governmental entities, and institutional clients through continuous innovation and large-scale global advisory networks.