The Impact of Medicaid Expansion on Continuous Enrollment: a Two-State Analysis

Background Discontinuous Medicaid insurance erodes access to care, increases administrative costs, and exposes enrollees to substantial out-of-pocket spending. Objective To assess the impact of Medicaid expansion under the Affordable Care Act on continuity of Medicaid coverage among those enrolled prior to expansion. Design Using a difference-in-differences framework, we compared Colorado, a state that expanded Medicaid, to Utah, a nonexpansion state, before and after Medicaid expansion implementation. Participants Adults ages 18-62 who were enrolled in Medicaid coverage in Colorado and Utah prior to expansion, from the Utah and Colorado All Payer Claims Databases, 2013-2015. Main Measures The primary outcomes were the duration of Medicaid enrollment and rates of disrupted coverage. Key Results Following Medicaid expansion, enrollees in Colorado gained an additional 2 months of coverage over two years of follow-up and were 16 percentage points less likely to experience a coverage disruption in a given year relative to enrollees in Utah. Conclusions Increasing Medicaid eligibility levels under the Affordable Care Act appears to be an effective strategy to reduce churning in the Medicaid program, with important implications for other states that are considering Medicaid expansion.