Migration over the U.S. southwest border in the past decade has been composed of growing numbers of undocumented and asylum-seeking families and children from Mexico and Central America, with larger increases starting in fiscal year (FY) 2017. By U.S. law, states must provide education to all children, regardless of immigration status. Yet sufficient information needed for policymaking is lacking, in particular about the ages and geographic locations of the children by state and district, needs for teachers and staff to accommodate these children, and experiences and good practices in schools. To fill this gap, the authors model the numbers of such children by state between FYs 2017 and 2019, review the federal and state policy landscapes for their education, and provide case studies of how schools are managing education for these children in Jefferson Parish Schools in Louisiana and Oakland Unified School District in California. The report specifically aims to help various stakeholders understand the broad range of issues and implications related to population increases in undocumented and asylum-seeking children over the southwest border, including the affordances and challenges of current federal and state immigration policies, numbers of school staff necessary to serve these students, and critical strategies and remaining challenges for supporting these children in U.S. school systems. The authors offer recommendations to school leaders, state officials, and federal policymakers about how to better provide education for this population and support schools in doing so.