"Effective January 2014, the Affordable Care Act establishes a new minimum Medicaid eligibility level of 138 percent of poverty for non-disabled adults who were not previously eligible for the program. As with current Medicaid, legal immigrants who have been in the country for five years or fewer are not eligible for this coverage. Nationally, 21.5 million currently uninsured nonelderly adults may meet the income and citizenship criteria to be eligible for Medicaid after the expansion. This brief uses the American Community Survey to describe the low-income uninsured adult population -- the target group for the Medicaid expansion under the Affordable Care Act -- by state. Many people in this target population have substantial health needs and face barriers to health care, and nearly half have incomes of 50 percent of poverty or less."