This research brief from UCLA Center for the Transformation of Schools examines the challenges faced by highly mobile youth (HMY), including students experiencing homelessness, involvement in foster care, migrant status, and detention within the juvenile legal system. The brief notes that approximately 1.9 million young people in the United States fall within these categories. Organized into three sections, the brief includes: (1) an overview of research supporting the need for cross-sector and coherent policy, (2) a review of existing fragmented policies, and (3) policy recommendations aimed at creating more integrated systems of care for HMY. The authors call attention to siloed policy approaches and advocate for a whole child approach across sectors such as education, housing, and health care. For educators, preparation programs, education leaders, and policymakers, this brief may serve as both an accessible introduction to the experiences of HMY and a resource for considering more coordinated systems of support and policy design.