Background: Little is known about the effectiveness of school district concussion policies on reducing the concussion prevalence among students. Methods: Data from the 2016 School Health Policies and Practices Study and 2017 Youth Risk Behavior Survey for 10 school districts were linked. The outcome variable was having a sports- or physical activity-related concussion during the 12 months before of the survey. Exposure variables were 2 district policies, including district-funded professional development and prioritizing return to the classroom before returning to athletics. Logistic regression models estimated the odds of a concussion among students in districts with one, both, or neither policy (referent). Results: In districts with district-funded professional development, the odds of students self-reporting [greater than or equal to]2 sports- or physical activity-related concussions were 1.4 times higher than in districts with neither policy. In districts with a policy prioritizing a return to the classroom before returning to athletics, the odds of students self-reporting [greater than or equal to]2 concussions were significantly lower (OR = 0.6) than in districts with neither policy. Conclusion: School district concussion policies may have positive effects by identifying and reducing multiple concussions among students.