When the Three Block Model of Universal Design for Learning (Katz, 2012a) is implemented, outcomes related to student academic and social engagement were investigated in this study. 631 students from Grades 1 to 12 attending ten schools located in two rural and three urban school divisions in Manitoba took part in the study. Intervention and control groups were assessed pre and during intervention for academic and social engagement. Student and teacher demographics, types of task and grouping structures being assigned were investigated to determine impacts on engagement. Students completed several measures of classroom climate, belongingness, student autonomy, and inclusivity/exclusivity, and a selected sample were observed to obtain detailed information about their engaged behavior. Data were analyzed using repeated measures MANCOVAs. The intervention significantly increased students' engaged behavior, particularly active engagement, and promoted social engagement through increased peer interactions, student autonomy, and inclusivity. (Contains 11 tables.)