Ever notice you’re filing to the same companies?

Blue Cross . . . Aetna . . . Blue Cross . . . Aetna — does it feel like you’re in a rut dealing with the same companies?

An American Medical Association study showed most of the 314 metro areas with Health Maintenance Organization and Preferred Provider Organization plans are often dominated by a major insurer like a Blue Cross Blue Shield licensee, Wellpoint, Aetna or UnitedHealthcare. The second-largest competitor is usually one of those four companies.

What’s it mean? Lack of competition means higher premiums by patients and employers and decreased earnings by doctors, says the AMA.