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

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.

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

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

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

3.97 million Medicaid beneficiaries.

Short- and long-term enrollment in the program.

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.

Primary estimates from a single state.

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.

Self-funded.