The purpose of this study was to develop and pretest a human trafficking screening tool (HTST) to capture the victimization experiences of young people involved in the child welfare (CW) and runaway and homeless youth (RHY) systems, as practitioners in these systems lacked such a consensus screening tool. The US Department of Health and Human Services (HHS) contracted with the Urban Institute to develop this tool in response to the 2014 Preventing Sex Trafficking and Strengthening Families Act, which mandated that federally-funded CW providers and agencies adopt human trafficking identification practices.1 This act followed two decades of research showing that CW and RHY youth are especially vulnerable to trafficking exploitation, given their unstable living circumstances, likely exposure to family abuse or neglect, and diminished socioeconomic resources.