Concentration in Health Insurance Markets

This interactive chart provides details on 1) enrollment in the overall individual market and the individual exchanges as measured by covered life-years, and 2) covered life-years in each state's individual exchange as a proportion of covered life-years in the overall individual market from 2015 through 2022.



West Virginia

Source: GAO analysis of data from the Centers for Medicare & Medicaid Services (CMS). | GAO-25-107194


The table below displays data for the selected state. Click here to download the data used in this graphic.



State Year Covered life-years, individual exchange Covered life-years, individual market Individual exchange covered life-years as a proportion of overall individual market (%)
West Virginia 2015 27,126 47,110 58
West Virginia 2016 29,543 45,766 65
West Virginia 2017 25,586 35,409 72
West Virginia 2018 21,326 27,087 79
West Virginia 2019 18,221 22,519 81
West Virginia 2020 17,384 20,859 83
West Virginia 2021 16,921 19,951 85
West Virginia 2022 21,099 23,675 89

  • We calculated the size of each market from 2015 through 2022 using covered life-years that issuers reported to Centers for Medicare & Medicaid Services or states. This measure is calculated as the average number of lives insured each month in the reporting year. Rather than a point-in-time measurement, this measure accounts for changes in enrollment that occur throughout the year.
  • Covered life-years is one of several ways to measure health insurance enrollment, so it may differ from other measures of market size.
  • We rounded market share values of less than 0.5 percent to zero.