US Marine Hospital, 2250 Northwestern Pkwy, Louisville, KY 40212, US

Humana is one of the nation's largest publicly traded health benefits companies, with approximately 7 million medical members. Humana offers coordinated health insurance coverage and related services including traditional and Internet-based plans, employer groups, government-sponsored plans and individuals through administrative service products, preferred provider organizations, consumer driven plans and government-sponsored plans. The company's specialty products are comprised of dental, life and disability insurance, which complement its core health offerings. Humana provides health benefits and related services to companies ranging from fewer than 10 to tens of thousands of employees. Michael B. McCallister has been the chief executive officer of Humana for more than six years. He has been with the health care provider for over 32 years. McCallister earned a BS degree from Louisiana Tech University, and a MBA from Pepperdine University. Humana has offices in 15 states including Arizona, Illinois, Georgia, Texas, Missouri and a branch in Puerto Rico. The company is located in Louisville, Ky.