The ACA Medicaid Expansion Led to Widespread Reductions in Uninsurance Among Poor, Childless Adults

Doctor weighs patient in clinic or hospital examination room.

Medicaid expansion reduced uninsured rate of poor, childless adults by 47 percent.



The Issue

In 2014, 26 states (including the District of Columbia) expanded Medicaid eligibility to 138 percent of the federal poverty level—or a yearly income of about $16,000/$22,000 for a family of one/two. Researchers estimated the impact of the ACA Medicaid expansion on uninsured rates of poor, childless adult citizens, by age, gender, race, income, education, and health.

Key Findings

  • The uninsured rate of poor, childless adults decreased by 47.1 percent between 2013 and 2015 under the ACA.
  • Coverage gains were particularly large among adults in fair or poor health, with a 61.7 percent decline in their uninsured rate, compared to 39.6 percent for those in good or better health.
  • In 2015, 17.9 percent of those with incomes less than 50 percent of the federal poverty level were uninsured, compared to 54.5 percent in nonexpansion states.



Coverage gains found among people with health problems suggest that the ACA Medicaid expansion reached a group of vulnerable adults who likely had limited access to affordable coverage before the ACA.

About the Urban Institute

The nonprofit Urban Institute is dedicated to elevating the debate on social and economic policy. For nearly five decades, Urban scholars have conducted research and offered evidence-based solutions that improve lives and strengthen communities across a rapidly urbanizing world. Their objective research helps expand opportunities for all, reduce hardship among the most vulnerable, and strengthen the effectiveness of the public sector. Visit the Urban Institute’s Health Policy Center for more information specific to its staff and its recent research.