Effects of Medicaid Expansion on Poverty Disparities in Health Insurance Coverage

Abstract Background: More than 30 States have either expanded Medicaid or considering expansion. The coverage gains from this policy is well documented, however, the impacts of its increasing coverage on poverty disparity are unclear at national level. Method: American Community Survey (2012-2018) was used to examine the effects of Medicaid expansion (ME) on poverty disparity in insurance coverage for nonelderly adults in the United States. Differences-in-differences-in-differences design was used to analyze the trends in uninsured rates (UR) by different poverty levels: 400% federal poverty level (FPL). Results: Compared with UR in 2012, UR in 2018 decreased by 10.75%, 6.42%, and 1.11% for 400% FPL. From 2012-2018, >400% FPL group continuously had the lowest UR and <138% FPL group had the highest UR. Compared with ≥ 138% FPL groups, there was a 2.54% reduction in uninsured risk after ME among <138% FPL group in ME states versus control states. After eliminating the impact of the ACA market exchange premium subsidy, 3.18% decrease was estimated. Conclusion: Poverty disparity in UR improved with ME. However, <138% FPL population are still at a higher risk for being uninsured.