In five large counties, payers own more than one-third of the primary care market, according to a study published in the July issue of Health Affairs Scholar found.
Payers, including Optum, Aetna, Humana and Cigna, owned 4.2% of the primary care market by service volume nationwide, but held significantly higher shares in some markets.
In 23 counties with more than 500,000 residents, insurers owned 10% or more of the primary care market.
Here are the large counties with the highest share of primary care providers owned by payers:
Snohomish County, Wash.: 45%
Contra Costa County, Calif.: 40%
Clark County, Nev.: 38%
Miami-Dade County, Fla.: 36%
Bexar County, Texas: 34%
Hudson County, N.J.: 30%
Hillsborough County, Fla.: 24%
Orange County, Fla.: 22%
El Paso County, Colo.: 20%
Westchester County, N.Y.: 20%
St. Louis County, Mo.: 19%
Los Angeles County, Calif.: 18%
Broward County, Fla.: 18%
Suffolk County, Mass.: 18%
Bernalillo County, N.M.: 18%
Hennepin County, Minn.: 18%
San Diego County, Calif..: 17%
Worcester County, Mass.: 15%
Hartford County, Conn.: 13%
Pinellas County, Fla.: 13%
San Bernardino County, Calif.: 13%
Cook County, Ill.: 12%
Summit County, Ohio: 11%
