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.



New Hampshire

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 (%)
New Hampshire 2015 41,375 62,937 66
New Hampshire 2016 45,734 104,328 44
New Hampshire 2017 43,911 97,373 45
New Hampshire 2018 38,918 90,823 43
New Hampshire 2019 38,629 49,652 78
New Hampshire 2020 40,321 51,164 79
New Hampshire 2021 44,832 56,617 79
New Hampshire 2022 48,327 60,524 80

  • 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.