States throughout the country have had very different marketplace enrollment rates based on Urban Institute projections of eligible populations. Those varied enrollment outcomes do not appear to follow any obvious patterns based on population size, political support for the Affordable Care Act, the type of marketplace or Medicaid expansion status. Based on interviews with diverse stakeholders in five states with relatively high enrollment in 2015—Connecticut, Florida, New Hampshire, Pennsylvania and Virginia—researchers have identified several factors that appear to have contributed to those states’ high enrollment outcomes.