New teachers need help. From day one, new teachers, largely on their own, are responsible for running a classroom and ensuring student learning, as well as fulfilling administrative requirements. Little wonder that 14% of new teachers leave by the end of their first year, 33% leave within three years, and almost 50% leave in five years (Ingersoll, 2003). Teachers cite lack of support and poor working conditions as primary factors. The Arizona K-12 Center, which provides professional development--including new teacher support--throughout Arizona, has studied the topic extensively in order to develop best practices for its programs. This has been especially relevant for the Arizona Master Teacher Mentor Program, which is designed to reduce new teacher attrition and improve performance. In this article, the authors share what they have learned about comprehensive induction programs.