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.
California
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 (%) |
|---|---|---|---|---|
| California | 2015 | 1,250,362 | 2,453,307 | 51 |
| California | 2016 | 1,318,108 | 2,449,742 | 54 |
| California | 2017 | 1,322,316 | 2,365,513 | 56 |
| California | 2018 | 1,362,293 | 2,234,832 | 61 |
| California | 2019 | 1,335,522 | 2,127,907 | 63 |
| California | 2020 | 1,508,779 | 2,248,756 | 67 |
| California | 2021 | 1,630,706 | 2,317,962 | 70 |
| California | 2022 | 1,708,528 | 2,302,110 | 74 |
- 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.