The purpose of this research was to investigate the individual experiences teachers, staff and administration at a secondary school in Pennsylvania have with implementing an MTSS framework with fidelity to successfully engage all students. Carroll's Theoretical Framework of Implementation Fidelity (2007) was used in this case study to help frame interview questions, guide design and analysis, as well as organize the data. Further, a literature review of school culture through the lens of an MTSS framework, implementation and student outcomes informed this study. The overarching research question for this study asked: How do teachers, staff and administration at a secondary school in Pennsylvania describe the implementation fidelity of an MTSS framework to successfully engage all students? A case study approach was used to explore and describe the perceptions of teachers, school counselors, a school psychologist and administrators using a rich-description of their experiences. It is evident that intentional implementation with fidelity of an MTSS framework at the secondary school level leads to greater student engagement and success in the areas of academic achievement, behavior and college and career readiness. In addition, the study revealed structures and supports necessary to facilitate the implementation of an MTSS framework including school culture, organizational context, ownership and systemic structures and how it might impact student outcomes. The finding of this study, along with identification and analysis of related themes, have the potential to inform the literature and similar secondary schools as they embark on the implementation of an MTSS framework. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]