National Managed Care Organizations

Top 15 Managed Care Firms, Ranked by Enrollment in 2007

Managed Care Organization	Total Enrollment
WellPoint, Inc.	30,242,907
United Health Group, Inc	17,080,995
Aetna, Inc.	13,861,191
Health Care Services Corporation	12,109,624
Humana, Inc.	11,358,428
CIGNA HealthCare Inc.	9,081,140
Kaiser Permanente	8,846,616
Highmark, Inc.	4,832,863
Blue Cross Blue Shield of Michigan	4,570,981
HIP Health Plan of New York	4,002,227
Independence Blue Cross	3,420,610
Horizon Blue Cross Blue Shield	3,377,000
Health Net, Inc.	3,298,563
Medical Mutual of Ohio	3,056,234
Blue Cross and Blue Shield of Florida, Inc.	2,987,955

Note: End of Year 2007 Data.