MMC vs CI Comparison

Marsh McLennan is a professional services firm that provides advice and solutions in the areas of risk, strategy, and human capital. The company operates through two main segments: risk and insurance services and consulting. In risk and insurance services, the firm offers services via Marsh (an insurance broker) and Guy Carpenter (a risk and reinsurance specialist). The consulting division comprises Mercer (a provider of human resource services) and Oliver Wyman (a management and economic consultancy). About half of its revenue is generated outside the US.

Cigna primarily provides pharmacy benefit management and health insurance services. Its PBM and specialty pharmacy services, which were greatly expanded by its 2018 merger with Express Scripts, are mostly sold to health insurance plans and employers. Its largest PBM contract is with the Department of Defense (current contract through 2029), and it recently won a multiyear deal with top-tier insurer Centene. In health insurance and other benefits, Cigna primarily serves employers through self-funding arrangements, and the company operates mostly in the US with 17 million US and 2 million international medical members covered as of December 2024.