This dissertation focuses on teacher and staff perceptions of Multi-Tiered Systems of Support (MTSS) implementation at the middle school level. MTSS implementation at the secondary level proves to be a daunting task which includes many complex facets. Ensuring that teacher and staff insights are sought out and taken into account when implementing school-wide programming such as MTSS can increase program success and fidelity. Specifically, this study examines three research questions: (1) How do middle school teachers and school support staff perceive implementation of a multi-tiered system of support? (2) How do these perceptions impact the buy-in and level of understanding of MTSS implementation? (3) In what ways do middle school teachers understand the MTSS framework? Utilizing a qualitative, single subject case study design methodology, this study sought to explore how teacher and staff perceptions and understanding of MTSS can impact implementation. The study took place in a suburban, western Pennsylvania middle school, in which the researcher is employed. The constant comparative method of coding was utilized in order to uncover themes related to the collected data. The following themes were uncovered through data analysis: support for all students and addressing individual student needs is a part of the MTSS process, the need for all staff to be involved in MTSS, insufficient communication with off-team teachers, discussion of forms as a part of the MTSS process, parental involvement was not discussed as a priority in responses, and procedures and logistics are discussed in relation to MTSS rather than the day to day implementation through working with students. Results of this study indicate that seeking opinions from teachers and staff regarding program implementation can provide valuable information for schools and districts to consider and highlights the importance of professional development focused on MTSS. [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.]