Sixty-two percent of uninsured children and two-thirds of uninsured, poor parents qualify for publicly funded health coverage programs but are not enrolled. This study assesses the potential impact of automatically enrolling children and parents in Medicaid and the State Children's Health Insurance Program (SCHIP) based on determinations of other means-tested programs. Current law permits states to cover some uninsured parents based on information in their children's Medicaid case files. However, current federal law forbids states from providing Medicaid or SCHIP based on the final income determinations of non-health agencies—the type of auto-enrollment that could reach eligible children. For such auto-enrollment to succeed, federal policymakers need to provide states with additional flexibility in determining eligibility and new resources for investing in information technology.