The IHS partially offsets lack of insurance for some uninsured AIANs, but important needs were potentially unmet.

Steep declines in the uninsured population under the Affordable Care Act (ACA) will depend on high enrollment among newly Medicaid-eligible adults. We use the 2009 American Community Survey to model pre-ACA eligibility for comprehensive Medicaid coverage among nonelderly adults. We identify 4.5 million eligible but uninsured adults. We find a Medicaid participation rate of 67% for adults; the rate is 17 percentage points lower than the national Medicaid participation rate for children, and it varies substantially across socioeconomic and demographic subgroups and across states. Achieving substantial increases in coverage under the ACA will require sharp increases in Medicaid participation among adults in some states.

No abstract

Children's participation in Medicaid and the Children's Health Insurance Program (CHIP) rose by 5 percentage points between 2013 and 2016. As a result, 1.7 million fewer Medicaid/CHIP-eligible children were uninsured in 2016. Participation was lower among adults than among children, and nearly 6 million Medicaid-eligible adults were uninsured in 2016.

Understanding why uninsured children with special health care needs do not participate in public programs is important, because these programs have the potential to cover almost all of this population. Initiatives to increase enrollment should yield real dividends given that the vast majority of low-income uninsured children with special health care needs have parents who say they would enroll their children in public coverage.