Health access and prevention under Arkansas' market-based Medicaid expansion

Arkansas expanded Medicaid in 2014 using a Section 1115 waiver that included premium assistance for beneficiaries to purchase private plans through the state's marketplace. The waiver was modified in 2017 to require partial premium payments and implemented work requirements in mid-2018, which were later rescinded by federal court order. We compared healthcare access and preventive service utilization in Arkansas vs states with traditional Medicaid expansions.

Using Behavioral Risk Factor Surveillance System data from 2011 to 2021, we applied difference-in-differences analysis to examine low-income non-elderly adults aged 18-64 in Arkansas and 3 demographically similar traditionally expanding states (Kentucky, Ohio, West Virginia). Outcomes included insurance coverage, usual source of care, annual checkups, cost-related care avoidance, and flu vaccination.

Compared to traditional expansion states, Arkansas' expansion was associated with greater increases in insurance coverage (+3.5% points, P < 0.001) and annual checkups (+6.1pp, P < 0.001). Both groups showed similar improvements in usual source of care and flu vaccination rates, and comparable reductions in avoided care due to cost.

Pre-existing gaps between Arkansas and traditional expansion states narrowed for insurance coverage and rates of annual checkups, while other outcomes improved in Arkansas at levels comparable to those observed in traditional expansion states.