Attainment of grade-level reading proficiency by fourth grade is pivotal to student academic success. In fourth grade, students shift from learning to read to reading to learn where they gain the ability to use their reading skills to access knowledge. Despite the connection between fourth grade reading proficiency and future academic success, national reading assessments demonstrate that one-third of America's fourth graders read below grade-level. Because reading proficiency scores at Southeast Elementary School are reflective of national statistics, the Multi-Tiered System of Supports in Reading (MTSS-R) program was initiated as a solution to mitigate the widening reading achievement gap at Southeast Elementary School. However, anecdotal concern about the school's readiness for implementation soon arose. This mixed-methods program evaluation combined data from a quantitative teacher survey assessing teacher self-efficacy for multi-tiered literacy instruction (TSEMLI), a qualitative semi-structured teacher focus group discussion, and ratings from the quantitative MTSS-R2 implementation readiness tool to assess whether current essential program components support the implementation readiness conditions required to fully implement MTSS-R during the 2023-2024 school year. The results of this study suggest that existing essential program components did not meet program implementation readiness conditions, that teachers possessed a commonly held understanding of the MTSS-R program purpose, and that teachers had a clear and common understanding of implementation roles and responsibilities, but that they lacked a commonly held understanding of essential MTSS-R program components. TSEMLI survey results indicated that teachers possessed moderate to high self-efficacy for multi-tiered literacy instruction (M = 4.07, SD = 0.14). A discussion of these results, to include recommendations for program improvement to the instructional leaders, could help support successful program implementation. [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.]