Coverage: Studies show that Medicaid expansion results in significant coverage gains and reductions in uninsured rates, both among the low-income population broadly and within specific vulnerable populations.
Access to care, utilization, affordability, and health outcomes: Most research demonstrates that Medicaid expansion positively impacts access to care, utilization of services, the affordability of care, and financial security among the low-income population. Studies have also shown improved self-reported health following expansion, but additional research is needed to determine effects on health outcomes.
Economic measures: Analyses find positive effects of expansion on multiple economic outcomes, despite Medicaid enrollment growth initially exceeding projections in many states. Studies also show that Medicaid expansions result in reductions in uncompensated care costs for hospitals and clinics as well as positive or neutral effects on employment and the labor market.
As the Trump Administration and Congress debate ACA repeal and replacement, gains in coverage and access as well as economic benefits to states and providers are at stake if the Medicaid expansion is repealed.
Research on the effects of Medicaid expansions under the Affordable Care Act (ACA) can help increase understanding of how the ACA has impacted coverage; access to care, utilization, affordability, and health outcomes; and various economic outcomes, including state budgets, the payer mix for hospitals and clinics, and the employment and labor market. Understanding these findings can help inform the debate over a repeal of the ACA (which would include the Medicaid expansion).
This summary reviews findings from 108 studies of the impact of state Medicaid expansions under the ACA published between January 2014 (when the coverage provisions of the ACA went into effect) and January 2017. (This is an update to an earlier issue brief, “The Effects of Medicaid Expansion under the ACA: Findings from a Literature Review,” that covered studies published through May 2016.) It includes peer-reviewed studies as well as free-standing reports, government reports, and white papers published by research and policy organizations, using data from 2014 or later. This brief only includes studies that examine impacts of the Medicaid expansion; it excludes studies on impacts of ACA coverage expansions generally (not specific to Medicaid expansion alone) and studies investigating potential effects of expansion in states that have not (or had not, at the time of the study) expanded Medicaid. In both the brief below and the tables, findings are separated into three broad categories: Medicaid expansion’s impact on coverage; access to care, utilization, affordability, and health outcomes; and economic outcomes for the expansion states.