Increasingly, third parties are working with schools and providing a coach (a skilled educator external to a school) who helps to facilitate reform. This paper explores some of the complexities of coaching by presenting a case study of a coach in her first year of facilitating math and science reform in a pseudonymous middle school in a Boston suburb. The school enrolled 900 students, predominantly white and middle class, and had approximately 70 teachers, including 12 math and science teachers. The coach came from the Center for Collaborative Education, a nonprofit organization that works with schools and districts to improve student learning by promoting and facilitating models of school reform. The center employs the following four school-based practices: (1) building leadership capacity and a professional collaborative culture; (2) improving learning, teaching, and assessment; (3) creating structures to support high achievement; and (4) fostering data-based inquiry and decision-making. The case study identified some of the challenges coaches face and some of the strategies used by coaches in their daily work. The paper also discusses some of the challenges coaches face. (WFA)