Since 1997, the Great Lakes Academy has provided leadership development for more than 800 teachers in a large metropolitan region of the Upper Midwest. Graduates of the 2-year program often describe their experience as transformative, life changing, and profound. To understand the meaning and impact of this transformation, the author used Mezirow's theory of transformative learning as a lens for analyzing the written reflections of recent graduates and interviews with teachers who completed the program 2 years earlier. Study findings highlight the importance of identity transformation as a critical step in the preparation of teacher leaders.