This paper presents findings from a three-year, qualitative study of teachers enrolled in a Masters of Teacher Leadership program. Researchers sought to understand the ways teachers’ beliefs about and understandings of teacher leadership were affected by their participation in a formal teacher leadership program, as well as the kinds of actions they took up as a result of this participation. Data indicate three significant ways participants’ work as teacher leaders was developed and enhanced, including: (a) identifying and amplifying their professional voice, (b) deepening and extending their voice as they plan, and (c) reframing their work/shift responsibility through constructing widening circles of influence and impact. Authors identify implications of their research for growing teacher leaders, school improvement and change, changing school culture, enhancing student engagement, and building new structures.