Cellphones have become part of students’ daily lives—powerful tools for learning, connection, and self-expression. At the same time, their use in schools can raise concerns around attention, stress, and safety. With more U.S. states moving toward regulation, education leaders have both a challenge and an opportunity to develop school cellphone policies that promote healthy, equitable, and effective technology use. This research brief translates developmental science and policy trends into evidence-based recommendations for K-12 leaders to support focused learning, healthy digital habits, and safer school environments.