There is little or no competition in Medicare Advantage markets in 97% of U.S. counties, according to a study released today by the Commonwealth Fund. Among 2,933 counties with at least 10 MA plan enrollees in 2012, only one county qualified as a competitive market and 80 as moderately competitive, based on the Department of Justice and Federal Trade Commission’s standard measure of market competition, the study found. “Even among the 100 counties with the greatest number of Medicare beneficiaries, 81% do not have competitive MA markets,” the authors said. “Market power is concentrated among three nationwide insurance organizations in nearly two-thirds of those 100 counties.”