Anthem Blue Cross and Blue Shield of Missouri is the largest provider of health care benefits in Missouri, serving approximately 900,000 medical members, according to the membership numbers from the Missouri Department of Insurance. The company has been serving Missourians for more than 65 years, and is an originator of prepaid health coverage. Anthem Blue Cross and Blue Shield administers health plans for individuals and groups. It is a member of the Blue Cross and Blue Shield Association. Based in Chicago, the Blue Cross and Blue Shield Association is the coordinating organization for the United States Blue Cross and Blue Shield Plans. It provides the tailored arrangements that enable the individual plans to form an effective nationwide network.