A new health policy issue brief from the Urban Institute uses 2010 census data and economic modeling to pinpoint characteristics of the roughly 15.1 million uninsured adults who could gain coverage if the Affordable Care Act’s Medicaid expansion were fully implemented. Distributions based on age, sex, parental status, race/ethnicity, and citizenship showed them to be a diverse group at both national and state levels. Overall, the newly-eligible are more likely to be male, white, and U.S. citizens.