This study examined the association between observers and students' reports of instructional support at the classroom-level, and whether students' off-task behavior predicted their perception of instructional support over time. The sample consisted of 1306 students and 79 teachers. Multilevel Structural Equation Modeling was applied to the analysis. The results showed a positive association between observed and student-reported instructional support at classroom-level, and the students' perceptions of their teachers' instructional support remained stable across the school year at the classroom- and student-levels. Students' off-task behavior was negatively related to perceptions of teachers' instructional support, and students high on off-task behavior in the fall reported decrease in (perceived) instructional support across the school year. This paper discusses the practical implications of this study and lists out directions for future research.