AMA Report: High Concentration in U.S. Commercial and Medicare Advantage Insurance Markets in 2024

The American Medical Association's 2024 report highlights significant concentration in U.S. commercial and Medicare Advantage (MA) health insurance markets. It reveals that 97% of commercial markets are highly concentrated, with dominant insurers holding over 30% market share in the vast majority of metropolitan statistical areas (MSAs). Almost half of MSAs have one insurer controlling at least 50% of the commercial market share. Similarly, Medicare Advantage markets show high concentration, with 97% of markets highly concentrated and at least one insurer holding over 30% market share in 90% of MSAs. In 24% of MSAs, a single insurer has at least 50% MA market share. Blue Cross Blue Shield leads commercial markets in metro areas, while Elevance holds the largest single insurer commercial market share at 21%. For Medicare Advantage, UnitedHealth Group is the leading insurer by market share in 44% of MSAs. These findings point to substantial insurer market dominance, which is a critical factor for regulatory scrutiny and industry stakeholders assessing competitive dynamics in health insurance sectors.