The present study is the first systematic review of instructional coaching components, methodologies, and outcomes reported in experimental and quasi-experimental group design studies examining the impact of coaching for school personnel supporting elementary-grade students with reading difficulties. Published and unpublished investigations (n = 30) from 2000 to 2023, which included 1863 teachers and interventionists and 21,133 kindergarten through 5-grade students with reading difficulties, were reviewed. All studies were reviewed using a structured review coding system with four dimensions (i.e., sample characteristics, coaching model elements, methodologies used, and outcomes reported; n = 77 variables). Strengths of reviewed coaching studies were the inclusion of multicomponent professional development with implementation training, diversity in student samples, and the use of statistical testing and reporting of effect sizes. Overall, 27 studies (90%) reported positive improvements in student reading performance at post-intervention. However, details reported for implementer and student characteristics, professional development components, and reading interventions implemented varied. Weaknesses of the literature were a lack of the following: participant inclusion and exclusion criteria, utilization of coaching in the use of reading screening and diagnostic measures to identify student skill-specific needs, implementation fidelity measurement, and follow-up data collection. Implications for research and practice are offered.