Headquartered in St. Louis, Missouri, Express Scripts provides integrated pharmacy benefit management services including network-pharmacy claims processing; home delivery pharmacy services; specialty pharmacy benefit management, through its subsidiary Accredo; benefit-design consultation; drug-utilization review; formulary management; and medical and drug data analysis services to manage drug plans for health plans, self-insured employers and government agencies (both as administrator of employee benefits and public assistance programs). One of its largest clients is the United States Department of Defense's Tricare program.

Official website: www.express-scripts.com