Long-Term Stability of Coverage Among Michigan Medicaid Beneficiaries : A Cohort Study

Ann Intern Med. 2023 Jan;176(1):22-28. doi: 10.7326/M22-1313. Epub 2022 Dec 6.

Abstract

Background: Medicaid, the primary source of insurance coverage for disadvantaged Americans, was originally designed as a temporary safety-net program. No studies have used long-run data to assess the recent use of the program by beneficiaries.

Objective: To assess patterns of short- and long-term enrollment among beneficiaries, using a 10-year longitudinal panel of Michigan Medicaid eligibility data.

Design: Primary analyses assessing trends in Medicaid enrollment among cohorts of existing and new beneficiaries.

Setting: Administrative records from Michigan Medicaid for the period 2011 to 2020.

Participants: 3.97 million Medicaid beneficiaries.

Measurements: Short- and long-term enrollment in the program.

Results: The sample includes 3.97 million unique beneficiaries enrolled at some point between 2011 and 2020. Among a cohort of 1.23 million beneficiaries enrolled in 2011, over half (53%) were also enrolled in Medicaid in June 2020, spending, on average, two-thirds of that period (67%) on Medicaid. These beneficiaries, however, experienced substantial lapses in coverage, as only 25% were continuously enrolled throughout the period. Enrollment was less stable when assessed from the perspective of newly enrolled beneficiaries, of whom only 37% remained enrolled at the end of the study period.

Limitation: Primary estimates from a single state.

Conclusion: For many beneficiaries, Medicaid has served as their primary source of coverage for at least a decade. This pattern would justify increasing investments in the program to improve long-term health outcomes.

Primary funding source: Self-funded.

MeSH terms

  • Cohort Studies
  • Humans
  • Insurance Coverage*
  • Medicaid*
  • Michigan
  • United States