Regional Educational Laboratory Midwest assisted Milwaukee Public Schools in developing a fidelity monitoring system for measuring schools' progress in implementing Response to Intervention (RTI). The study examined the ratings produced by that system to determine the system's reliability, schools' progress in implementing RTI, and whether ratings were related to school characteristics. Two years after rolling out RTI, 53 percent of participating schools were implementing it with adequate fidelity. Average implementation ratings suggest that priority schools need more coaching and professional development on RTI than do focus schools and other schools and that most schools could benefit from coaching and professional development on tier 3 instruction and instruction for diverse students. Implementation fidelity ratings were related to the percentage of teachers with advanced credentials, retention of licensed staff, percentage of economically disadvantaged students, and percentage of students suspended during the school year. This brief summarizes the findings to the full study. [For the full study, "Measuring the Implementation Fidelity of the Response to Intervention Framework in Milwaukee Public Schools. REL 2017-192," see ED570888.]