Although education is in many ways a responsibility of states and localities, the U.S. federal government also has an important role to play. National laws, court rulings, and policy guidance help ensure that English Learner (EL) and immigrant-background students have equitable access to a meaningful education. It is then up to states and school districts to color in many of the details as they implement these protections in their free, public primary and secondary school systems. This EL Insight lays out seven key ways the U.S. government protects the educational rights of EL and immigrant-background students, including those with Limited English Proficient and unauthorized-immigrant family members. It also explains the legal framework behind these rules, who enforces them, and how they can be seen in action in schools across the country. Some of the policies highlighted in this brief--such as using a two-step home language questionnaire and English assessment to identify which students are ELs--are well established and look similar across the country. Others, such as requirements for what credentials teachers must have to work with ELs, vary considerably. And while some legal protections have become a basis for strengthening broader educational policy, many have limitations or have fallen short their implementation. This brief is the latest in a series of English Learner Insights, which also includes an introduction to finding and using EL data and to the instructional models schools use to serve ELs.