State Enacted Legislation

HMO Enrollment

Kaiser Foundation Health Plan, Inc.

4,935,832

AETNA Health Inc.

2,591,978

Blue Shield of California

1,057,186

Coventry Health and Life Insurance Company

992,012

Blue Cross Blue Shield of Massachusetts

828,565

Blue Cross and Blue Shield of Illinois

796,932

Blue Cross Blue Shield of Michigan

576,133

CareFirst BlueCross BlueShield

529,902

HIP Health Plan of New York, Inc.

425,766

Kaiser Foundation Health Plan of the Northwest, Inc.

409,648

Source: AIS's Directory of Health Plans: 2010, Copyright © 2010 Atlantic Information Services.