News Release

A Comprehensive Review of Research Finds That the ACA Medicaid Expansion Has Reduced the Uninsured Rate and Uncompensated Care Costs in Expansion States, While Increasing Affordability and Access to Care and Producing State Budget Savings   

Recent Research Finds an Association with Some Improved Health Outcomes


Multiple studies over the last five years find that the Affordable Care Act’s Medicaid expansion has increased health coverage, affordability, and access to care while producing budget savings for states and reductions in uncompensated care costs for hospitals and clinics, according to a KFF review of more than 300 studies and policy reports. Thirty-six states and the District of Columbia have adopted the ACA Medicaid expansion. The literature review provides a useful reference on the effects of expansion at a time when more states are considering expansion, including some through waivers. At the same time, the Texas v. U.S. legal challenge to the ACA could roll back the Medicaid expansion as well as other provisions of the health law. The new analysis is the first significant update to KFF’s literature review of research on the effects of Medicaid expansion in more than a year. While significant expansions in coverage had been documented in the earlier review, recent studies were more focused on utilization, access, affordability and outcome metrics.  Other key findings include:
  • Some studies show that improved access to care and greater utilization of care is leading to increases in the diagnosis (and early diagnosis), of cancer and other conditions, and to increased prescriptions for medications used to treat opioid use disorder and opioid overdose.
  • A growing body of research finds an association between Medicaid expansion and certain measures of health outcomes, including improvements in self-reported health as well as improvements in cardiovascular mortality rates and cardiac patient surgery outcomes. Studies also show that Medicaid expansion improves affordability of health care and results in improvements in broader measures of financial stability.
  • Other studies did not find significant changes associated with expansion on certain measures of quality of care or health outcomes likely because the studies were narrow in scope or not enough time had elapsed to measure change.
  • Findings on the Medicaid expansion’s effect on provider capacity are mixed, with some studies showing increased availability of primary care appointments and others finding longer wait times or increased difficulty getting appointments with specialists.
While a number of studies document net budget savings and other fiscal benefits like increased revenue and jobs for states as a result of the expansion, this may in part be because the federal government covered 100 percent of the cost from 2014 to 2016. The federal share is phasing down and states will ultimately be required to cover 10 percent of the cost, which could influence the net effects over time (although some state reports project a net fiscal benefit even as the state share for the expansion increases). There is limited research examining the fiscal effects at the federal level from the additional expenditures for the Medicaid expansion or the revenues to support that spending. The literature review covers studies, analyses and reports published by government, research and policy organizations between January 2014 and June 2019, using data from 2014 or later.

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The independent source for health policy research, polling, and news, KFF is a nonprofit organization based in San Francisco, California.