AMA publishes new study monitoring competition in U.S. health insurance markets

Sept. 29, 2021

The American Medical Association (AMA) published the newest annual edition of Competition in Health Insurance: A Comprehensive Study of U.S. Markets with findings demonstrating the rise of highly concentrated markets for health insurance.

The updated study analyzed market concentration and health insurer market shares for 384 metropolitan statistical areas (MSAs), the 50 states and the District of Columbia. For the first time, the study also presents national-level market shares for the 10 largest health insurers in the U.S. The study’s findings show most health insurance markets in the U.S. are highly concentrated leaving millions of Americans with more limited health insurer options. 

The AMA’s latest study of competition in commercial health insurance markets shows: 

  • Seventy-three percent (280) of MSA-level markets were high concentrated according to federal guidelines. 
  • Forty-six percent (178) of MSA-level markets had one insurer with a share of 50% or more. 
  • Between 2014 and 2020, the share of highly concentrated markets rose from 71% to 73%. 
  • Fifty-four percent of markets that were already highly concentrated in 2014 became even more concentrated by 2020. 
  • The health insurers with the highest market share in the most MSA-level markets were: 1. Anthem (80 MSAs), 2. Health Care Service Corp. (44 MSAs), 3. UnitedHealth Group and Blue Cross Blue Shield of Florida (each with 22 MSAs apiece), and 4. Highmark and Kaiser (each with 20 MSAs apiece). 
  • The 10 largest health insurers in the U.S. at the national-level by market share were: 1. UnitedHealth Group (15%), 2. Anthem (12%), 3. Aetna (11%), 4. Cigna (10%), 5. Kaiser (7%), 6. Health Care Service Corp. (6%), 7. Blue Cross Blue Shield of Michigan (2%), 8. Blue Cross Blue Shield of Florida (2%), 9. Blue Shield of California (2%), and 10. Centene (2%). 

AMA release.