Families migrate to the United States for opportunity. Whether they leave extreme poverty or violence or reunite with relatives who made the move before them, immigrants seek opportunity. Sometimes circumstances force families to make tough decisions. Sometimes circumstances and tough decisions manifest in families entering the United States without legal documentation. These families become America's undocumented. The children who migrate as part of these families become undocumented students. This transition to undocumented status is accompanied by limited opportunities, particularly for employment, and increasingly for higher education. Nevertheless, undocumented students continue their families' struggle for opportunity every day on college and university campuses. Student affairs professionals are vested with the responsibility for assisting and supporting the academic and social success of all students, including those from undocumented families. This chapter outlines the legal context for undocumented students in higher education and provides direction for policymakers in student affairs offices serving these students. The authors explore how law and policy matter in undocumented students' lives. They also provide additional resources for student affairs professionals to consult when crafting policy and developing expectations for effective practice in the support of undocumented students. (Contains 12 resources.)