News Release

New Analysis Summarizes Recent Research on the Effects of ACA Medicaid Expansion, Providing Context for Renewed Expansion Debates in States

New federal financial incentives for Medicaid expansion and the increased reliance on Medicaid as a coverage safety net during the pandemic have renewed debate in the 12 states that have not adopted the Medicaid expansion under the Affordable Care Act.

A new KFF literature review provides context for these expansion debates by summarizing evidence from nearly 200 studies about the effects of Medicaid expansion that were published between February 2020 and March 2021. These studies generally have found beneficial effects across a range of areas, including:

  • Increased coverage and access to care among populations with cancer, chronic disease, and/or disabilities. Studies also find that Medicaid expansion has improved overall mortality rates as well as mortality rates associated with some specific health conditions, such as different types of cancer, cardiovascular disease, and liver disease.
  • Improvements in outcomes related to sexual and reproductive health, including increased postpartum insurance coverage and use of care among pregnant women and mothers.
  • Improvements in access to care and outcomes related to substance use disorder (SUD) as well as other mental health care.
  • Beneficial economic impacts on state budgets, hospitals, and other providers.
  • A narrowing of racial disparities in coverage and certain health outcomes, with more limited evidence suggesting reduced racial disparities in access to and use of care.
  • Improvements in different social determinants of health, including individual economic stability and access to care in rural areas.

The new analysis of recent studies builds on an earlier report (examining over 400 studies) concluding that expansion is linked to gains in coverage; improvements in access, financial security, and some measures of health status/outcomes; and economic benefits for states and providers.

Along with the benefits, Medicaid expansion brings increases in Medicaid spending for states and especially for the federal government, which covers 90 percent of the cost.

For the full literature review, as well as other data and analyses related to ACA Medicaid expansion, visit

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