Moving opportunistically: Interstate migration after medicaid expansion

The large-scale expansion of Medicaid eligibility following the Affordable Care Act provides an ideal setting to explore whether changes to state-provided health insurance benefits predict migration across state lines. Using the American Community Survey's person-level data from 2009 to 2019 about moving during the prior 12 months, we examine whether Medicaid's selective expansion after the Affordable Care Act prompted in-migration to states that greatly expanded Medicaid eligibility for the populations most targeted by the expansion. We find that states expanding Medicaid by the largest margin was related to higher in-migration, equating to 0.23 percentage points greater annual population growth in the target population, 0.42 percent for the disabled subpopulation, and 0.25 percent for the parent subpopulation. Our results translate to 56,659 interstate moves after Medicaid enrollment growth. The effect was concentrated among individuals who previously lived close to a state's border. The implications of this study are that high-needs individuals in certain states may be impacted by welfare magnets and modestly prone to being undercounted in projected government expenditures.