Top 25 U.S. Health Insurance Companies, By Market Share

1. Unitedhealth Group

2. Wellpoint Inc. Group

3. Kaiser Foundation Group

4. Humana Group

5. Aetna Group

6. HCSC Group

7. Cigna Health Group

8. Highmark Group

9. Coventry Corp. Group

10. HIP Insurance Group

11. Independence Blue Cross Group

12. Blue Cross Blue Shield of New Jersey Group

13. Blue Cross Blue Shield of Michigan Group

14. California Physicians' Service

15. Blue Cross Blue Shield of Florida Group

16. Health Net of California, Inc.

17. Centene Corp. Group

18. Carefirst Inc. Group

19. Wellcare Group

20. Blue Cross Blue Shield of Massachusetts Group

21. UHC of California

22. Lifetime Healthcare Group

23. Cambia Health Solutions Inc.

24. Metropolitan Group

25. Molina Healthcare Inc. Group