Paul Stringer
Slide 1 of 12
Benefit advisers, employers and other industry insiders fear merger and acquisition activity in the health insurance industry is eroding market competition, a trend that could lead to increased premiums for employers and individuals. Recent research from the American Medical Association identified the top 10 states with the least competitive HMO markets based on market concentration levels as determined by the Herfindahl–Hirschman Index or HHI—a measure used by the U.S. Department of Justice and the Federal Trade Commission.

The HHI number can range from close to zero to 10,000. DOJ considers a market with a result of less than 1,000 to be a competitive marketplace; a result of 1,000-1,800 to be a moderately concentrated marketplace; and a result of 1,800 or greater to be a highly concentrated marketplace.