The response to intervention (RtI) framework assists schools in identifying students who struggle to close achievement gaps. The problem examined for this study was lack of fidelity in the application of RtI, possibly leading to an increase in special education referrals. The purpose of this basic qualitative study was to gain a better understanding of the perceived needs of teachers to implement RtI with fidelity. The goal was to use the results to create professional development (PD) for teachers to implement RtI with fidelity. The conceptual framework was based on Ely's conditions of change and Rogers's diffusion of innovation theory. The research questions focused on the implementation of RtI and the perceptions of teachers regarding fidelity in implementing RtI in the classroom. Participants were 10 elementary teachers from 6 different schools. Data were gathered through semistructured interviews of the 10 teachers using RtI in the classroom and were analyzed through a priori and open and thematic coding. Findings included common themes related to the need for PD, including knowledge, clear guidelines, resources, and coaching. Based on the findings, a project was created for a 3-day PD for teachers in the district, along with professional learning communities to support teachers after the training and individual coaching for specific teachers' needs to refine the implementation of RtI with fidelity. The analyzed data were used to provide recommendations and a project that could be used to address the fidelity of the ongoing application of RtI in the local setting. This study may contribute to positive social change by promoting early intervention of at-risk students, targeted interventions at students' instructional level, fewer referrals to special education, and success for students in the appropriate and least restrictive environment. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]