Social workers, educators, legal advocates, and physicians and other health care professionals depend on data to diagnose concerns, develop treatment plans, and evaluate outcomes for foster children, who account for 425 000 children in the US annually. However, data concerning child welfare issues are often substantially decentralized, protected, and even suppressed in the US, limiting the effectiveness of interventions and subsequent social and health outcomes. Research inquiry and implementation of effective polices are limited by the lack of a population health infrastructure to establish the evidence for a more effective US child welfare system. While health information exchanges are used by third-party payers in managing risk of their subscribers, these data, with rare exception, have not been used with other sector data systems to affect relevant and meaningful outcomes.