School leaders seek to remove students with disabilities with serious disruptive and/or violent behaviors from school and attempt to work around the disciplinary requirements of Individuals with Disabilities Education Act (IDEA). When faced with the practical challenges such as increased staffing shortages, mental health concerns, and school shootings, what should administrators do to prevent illegal exclusionary discipline? We conducted a legal analysis of the relevant case law, policy guidance, and brain science literature. Ultimately, we found that the law requires schools to consider positive behavior supports, but schools are implementing these supports too late. Instead, schools should increase positive behavioral supports before students’ behavior escalates. We provide practical recommendations how school leaders can avoid illegal exclusionary discipline by proactively increasing positive behavioral supports.