Response to Intervention (RtI) has gained increased attention with the reauthorization of the Individuals with Disabilities Education Improvement Act. Since RtI was introduced at the policy level as a mechanism for use in the learning disability identification process, much of the implementation work has focused on this application. School-based implementation of RtI has occurred quickly in response to federal legislation, with little focus on fidelity. Regular and consistent monitoring of implementation fidelity can provide the data required to improve implementation and student performance. This discussion will include a brief review of the literature regarding implementation fidelity and then provide a framework for designing a fidelity system for RtI models. Further systematic research in this area is needed to support the RtI implementation that is currently under way in schools across the country. (Contains 4 tables.)