Drawing on a statewide study of Florida middle-school reading coaches, this article examines what constitutes, contributes to, and is associated with high-quality coaches and coaching. Authors find that coaches generally held many of the qualifications recommended by state and national experts and principals and teachers rated their coaches highly on many indicators of quality. However, several common concerns about recruiting, retaining, and supporting high-quality coaches emerged. Estimates from models indicate that a few indicators of coach experience, knowledge, and skills had significant associations with perceived improvements in teaching and higher student achievement, although the magnitude of the latter relationship was quite small. Findings suggest that although possessing strong reading knowledge and instructional expertise may be important for coaching, it may not be sufficient. (Contains 1 figure, 5 tables and 11 footnotes.)