This qualitative case study was an examination of the perspectives, beliefs, and experiences of rural reservation elementary teachers' implementation of and professional development with a multitiered system of support (MTSS) framework as it relates to reading and collective teacher efficacy. Teacher participants experienced adherence to the Reading Mastery program instruction and assessment components in their pedagogy with fidelity and an increase in self-efficacy related to delivering the program. They experienced a shift in thinking in their data-based decision-making after gaining professional development and conveyed an understanding of evidence-based practices in instruction, intervention, and assessment as essential elements of the MTSS framework. Feelings of self-efficacy and collaborative opportunities contributed to a collective teacher efficacy in PLC meetings and data-based decision-making. Although participants experienced shared leadership and collaboration through the PLC process, a focus on Reading Mastery program components minimized their PLC experiences. Three implications for practice emerged from the findings. The emphasis on one program (Reading Mastery) led to only that one performed and a lack of transferable knowledge, which meant teachers did not have opportunities to create more independent readers. Furthermore, the PLC process based on the reading program resulted in a minimized experience, as teachers did not show evidence of answering the four questions of a PLC. Continued professional development and coaching in the reading progression and MTSS as a framework is an instructional need to help participants in balanced literacy and assessment practices. [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.]