Schools are increasingly using multi-tiered prevention models to address the academic and behavior needs of students. The foundation of these models is the implementation of universal, or Tier 1, practices designed to support the academic and behavioral needs of the vast majority of students. To support teachers in the use of effective Tier 1 classroom practices, researchers and practitioners need reliable and valid measures of these practices that are sensitive to change over time. The purpose of this study was to examine the reliability and validity of the "Brief Classroom Interaction Observation-Revised" (BCIO-R), which is a direct observation measure of classroom Tier 1 instructional and classroom management practices for use in elementary school classrooms. Findings indicate that the BCIO-R can be reliably implemented in the classroom context. In addition, the measure is associated with important teacher-reported constructs such as efficacy in classroom management and burnout. Furthermore, the measure is sensitive to change as indicated by demonstration of improvement in classroom management variables among teachers who received a universal classroom management intervention versus teachers who did not receive training. Having reliable and valid measures to evaluate and monitor teacher use of universal classroom practices can be useful when consulting to support teachers and improve student outcomes.