The heterogeneity in effects of ACA Medicaid expansion by state-level factors

Due to the lack of health coverage, low-income non-elderly adults in the US have historically had worse health outcomes and access to healthcare than higher-income individuals. As a key provision under the ACA, states have options to expand Medicaid for any individual with income below 138% FPL. As states might differ dramatically in many ways, uncovering how these differences can modify the expansion effects on their populations is essential to fully understand the effectiveness of the expansions.

The first study examines the heterogeneity in the Medicaid expansion effects on cancer screening by the availability of primary care providers. It concludes that Medicaid expansions are associated with the increased use of multiple different cancer screenings only in states with a greater supply of primary care providers. The second study investigates the effects of the Medicaid expansions on dental services considering the extensive variations in the levels of Medicaid adult benefits. The estimates indicate that expanding Medicaid with covering beyond emergency-only dental benefits can increase the use of both preventive dental services and dental treatments. The third study evaluates how the effects of Medicaid expansions are varied across subgroups of expanding states by their pre-expansion parent Medicaid income eligibility. The study finds substantial differences in the Medicaid expansion impacts on coverage and access among low-income mothers across expanding states with different levels of income eligibility expansions.

Findings from this dissertation reaffirm that Medicaid expansion effects could differ widely across state-level heterogeneities, and the local differences should be carefully assessed for policy implementation.