Overview
Twice per year, CHIA updates its detailed Enrollment Trends analysis for the most recent two-year period to provide insight into the types of health insurance in which Massachusetts residents are enrolled. The latest edition covers the period between September 2023 and September 2025 and includes breakouts by payers and product types in private commercial and public market sectors.
In this report, coverage is defined by unique Massachusetts residents with primary, medical membership in the 12 largest commercial payers, MassHealth (Medicaid), or Medicare.
This edition of Enrollment Trends reporting includes a detailed databook and technical appendix. The next iteration of the report, expected in fall 2026, will include an interactive dashboard, a detailed databook, and technical appendix.
Enrollment measures are also reported in CHIA’s Annual Report on the Performance of the Massachusetts Health Care System.
Previous Enrollment Trends Materials
In addition to bi-annual enrollment trend reporting, CHIA produced monthly enrollment data summaries between May 2020 and June 2021 to provide rapid insight into the impact of COVID-19 on insurance coverage in the Commonwealth.
- Enrollment Monitoring through June 2021 (PDF)
- Databook (Excel)
- Enrollment Monitoring through March 2021 (PDF)
- Databook (Excel)
- Enrollment Monitoring through February 2021 (PDF)
- Databook (Excel)
- Enrollment Monitoring through January 2021 (PDF)
- Databook (Excel)
- Enrollment Monitoring through December 2020 (PDF)
- Databook (Excel)
- Enrollment Monitoring through November 2020 (PDF)
- Databook (Excel)
- Enrollment Monitoring through October 2020 (PDF)
- Databook (Excel)
- Enrollment Monitoring through September 2020 (PDF)
- Databook (Excel)
- Enrollment Monitoring through August 2020 (PDF)
- Databook (Excel)
- Enrollment Monitoring through July 2020 (PDF)
- Databook (Excel)
- Enrollment Monitoring through June 2020 (PDF)
- Databook (Excel)
- Enrollment Monitoring through May 2020 (PDF)
- Databook (Excel)