Background: School policies can change practices on a relatively permanent basis. This study investigated adoption and implementation of state-level policies specifying minutes (or percent) of physical activity in physical education (PE) or during school. Methods: Policies were identi?ed from existing databases and rated as having weak, moderate, or strong wording. Interviews with state-level PE coordinators were conducted to investigate the level of implementation, monitoring, and enforcement of the identi?ed policies. Results: Sixteen states had a policy that met inclusion criteria (19 policies total); 11 states had a policy addressing minutes of physical activity during school, 2 had a policy addressing percent of PE time to be spent in physical activity, and 3 had policies addressing both. None of the 19 policies were rated as having strong wording and 5 were rated as having moderate wording. The range in minutes of physical activity per week addressed in the policies was 60 to 300. Four of the 5 (elementary) and 5 of 5 (middle) policies addressing percent of PE spent physically active speci?ed 50%. The only monitoring efforts reported consisted of schools self-reporting progress to the state. Conclusions: More states need to adopt school physical activity policies and policy language needs to be more speci?c to prevent potential loopholes. Monitoring and evaluation strategies, beyond school self-report, are likely needed for these policies to lead to increases in physical activity. (Contains 4 tables.)