In 2013 and 2015 Oregon enacted legislation that shifted school discipline policies from a zero-tolerance approach to one that emphasizes preventing behavioral problems and reducing unnecessary suspensions and expulsions. Suspensions and expulsions are often referred to as exclusionary discipline because they remove students from classroom instruction. This study examined the association between state-level policy reforms and suspension and expulsion rates for grades K-12 in Oregon public schools. The findings suggest that the policy shift has led to some short-term progress on two of the state's main goals--reducing unnecessary removal of students from classroom instruction for disciplinary reasons and reducing exclusionary discipline for weapons offenses that do not involve firearms. Across all grade spans the use of exclusionary discipline declined from school year 2008/09 to 2016/17, with greater reductions for grades 9-12 and 6-8 than for grades K-5. Oregon's policy reforms were associated with short-term reductions in some forms of exclusionary discipline after pre-policy trends and other factors were adjusted for. For example, the 2013 policy reforms were associated with short-term reductions in the number of out-of-school suspensions per student for grades 9-12 and 6-8, and the 2015 policy reforms were associated with a reduction in out-of-school suspensions for grades K-5. For grades 6-8 and K-5 the policy reforms were also associated with reductions in the number of expulsions per student. However, many disciplinary actions reverted--or appeared to be reverting--toward pre-policy trends within a few years. Meanwhile, for all grade spans the policy reforms were not associated with reductions in the use of in-school suspensions after other factors were adjusted for. The declining rates of exclusionary discipline indicate progress, but growth in out-of-school suspensions in recent years suggests the need for further monitoring and additional support. For example, strengthening efforts to reduce suspensions for minor infractions, especially for grades 9-12 and 6-8, could reduce unnecessary suspensions overall--a priority of Oregon's school discipline policy reforms. [For the appendixes, see ED607761; for the study snapshot, see ED607762.]