The AMA recently released its 2021 Update to Competition in Health Insurance: A Comprehensive Study of U.S. Markets (PDF). This study reports the two largest health insurers' market shares and market concentration (HHI) levels in each of the 384 metropolitan statistical areas (MSAs), the 50 states and the District of Columbia.
For the first time, the report also presents national-level market shares for the 10 largest health insurers in the U.S. The study finds that the average HHI increased by 171 points to 3494 between 2014 and 2020, while the share of markets that are highly concentrated rose from 71% to 73%. 57% of markets experienced an increase in the market concentration level (HHI). Among those markets, the average increase was 531 points. 54% of markets that were already highly concentrated in 2014 became even more concentrated by 2020.
The study also finds that a Blue Cross Blue Shield affiliate had the largest market share in 81% (311) of MSAs. Finally, UnitedHealth Group was the largest commercial health insurer at the national level, while Centene was the largest insurer in the exchanges. Learn more.