The previous Assuring Better Child Health and Development (ABCD) initiatives have helped 25 states launch projects to promote structured developmental screening through policy and practice change. As practitioners step up their identification of young children with developmental concerns, however, they are presented with a new challenge: effectively referring families to appropriate intervention services and coordinating their care with other developmental service providers. This complex problem, which requires cross-agency and public–private collaboration within each state, is the proposed focus for the next ABCD initiative led by the National Academy for State Health Policy (NASHP). The project team will begin background work by surveying states' care coordination policies and practices, fostering dialogue across states, and undertaking planning efforts. Concurrently, NASHP will continue to support states' efforts to sustain their achievements in expanding developmental screening.