Investigators at Urban Institute Describe Findings in Insurance (Reduced Medicare Advantage Insurer Concentration Associated With Small Improvements In Market Outcomes, 2013-23): Insurance

2025 NOV 14 (NewsRx) -- By a News Reporter-Staff News Editor at Health Policy and Law Daily -- Data detailed on Insurance have been presented. According to news reporting originating in Washington, District of Columbia, by NewsRx journalists, research stated, “Medicare Advantage (MA) enrollment has grown rapidly over recent years, and enrollees may now choose from among a large number of MA plans. However, the market remains highly concentrated, with a few very large insurers.”

Financial support for this research came from National Institute for Health Care Reform.

The news reporters obtained a quote from the research from Urban Institute, “Using MA administrative data, we analyzed trends in insurer concentration during the period 2013-23 and its relation to MA payments and plan characteristics. We documented a significant shift toward less concentration, but concentration remained high. The average number of insurers per county increased, and the Herfindahl-Hirschman Index measure of market concentration declined. Reduced concentration was associated with lower Medicare payments and individual premiums, higher plan rebates, and less enrollee cost sharing. The estimated effects, however, were quantitatively small.”

According to the news reporters, the research concluded: “Our findings suggest that further reductions in MA insurer concentration may yield only modest benefits for Medicare beneficiaries and the program unless concentration falls well below current levels.”

This research has been peer-reviewed.

For more information on this research see: Reduced Medicare Advantage Insurer Concentration Associated With Small Improvements In Market Outcomes, 2013-23. Health Affairs, 2025;44(10):1244-1249. Health Affairs can be contacted at: Project Hope, 7500 Old Georgetown Rd, Ste 600, Bethesda, MD 20814-6133, USA.

Our news correspondents report that additional information may be obtained by contacting Bowen Garrett, Urban Institute, Washington, DC 20037, United States.

The direct object identifier (DOI) for that additional information is: https://doi.org/10.1377/hlthaff.2025.00119. This DOI is a link to an online electronic document that is either free or for purchase, and can be your direct source for a journal article and its citation.

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