This Report to the Congress responds to a requirement in the Adam Walsh Child Protection and Safety Act of 2006 that directs HHS to study the feasibility of a national registry of child maltreatment perpetrators, also known as a national child abuse registry. It follows up on an interim report issued in 2009. The feasibility study includes several components. We surveyed key informants in the states to gain a better understanding of the content and operations of state existing state registries. We reviewed relevant court cases in which aspects of states' child abuse registries have been challenged. Finally, through a prevalence study we sought information to better quantify the potential benefits of a national registry of child maltreatment perpetrators, in particular by estimating the number of perpetrators nationally who have been substantiated as perpetrators of child abuse and neglect in multiple states.