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.
Massachusetts
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 (%) |
|---|---|---|---|---|
| Massachusetts | 2015 | -- | 231,451 | -- |
| Massachusetts | 2016 | -- | 301,645 | -- |
| Massachusetts | 2017 | -- | 326,528 | -- |
| Massachusetts | 2018 | 252,315 | 332,094 | 76 |
| Massachusetts | 2019 | 281,022 | 356,088 | 79 |
| Massachusetts | 2020 | 293,236 | 363,620 | 81 |
| Massachusetts | 2021 | 267,581 | 333,312 | 80 |
| Massachusetts | 2022 | 228,209 | 290,161 | 79 |
- 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.
- Massachusetts is not included in this figure for 2015 through 2017 because we were unable to obtain data on covered life-years for this time.