Research for Action’s third and final report completes a three-year evaluation study of the Pennsylvania High School Coaching Initiative (PAHSCI). This report presents lessons from the PAHSCI model of school-based instructional coaching and mentoring as a vehicle for job-embedded professional learning. Reporting from an analysis using qualitative methods including interviews of teachers and coaches and observations of classroom lessons, the report examines the influence of coaching on the implementation of research-based literacy practices applicable across the content areas. It explores student engagement and coaching’s contribution to teachers’ ability to reflect on and change classroom practice. Finally, this report discusses the strengths and challenges of PAHSCI’s influence on the individual, the school, the district and the state to link learning and build sustainability.