Educators nationwide are receiving training through Language Essentials for Teachers of Reading and Spelling® (LETRS®), a program rooted in a structured literacy that encompasses all five essential components of literacy recommended by the National Reading Panel (NRP, 2000): phonemic awareness, phonics skills, fluency, vocabulary, and comprehension. However, professional development alone is not enough for long-term behavior change in instructional practices (Desimone & Garet, 2015; Joyce & Showers, 1982, 2002; Kraft et al., 2018). Coaching may be a way supplement to professional learning sessions and help teachers apply what they learned in their daily class instruction (Carlisle & Berebitski, 2010; Golden et al., 2021; Joyce & Showers, 1982). A concurrent multiple baseline design across teachers evaluated the degree peer coaching, a type of coaching, affects teacher implementation adherence of LETRS-based instruction. Results indicated all teacher dyads implemented the Ohio Peer Coaching Model with high adherence and all improved or sustained high levels of adherence to LETRS-based instruction. Notably, teachers with lower adherence levels relative to their peer coach were able to achieve a similarly high level of adherence by the end of the study, closing the gap. Overall, teachers found peer coaching to be an acceptable form of support. Several challenges hindered effective measurement of student outcome data and are unable to be interpreted. Limitations, implications, and future directions are discussed. [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/en-US/products/dissertations/individuals.shtml.]