Comprehensive reviews of empirical research on teacher leadership have revealed that this body of research remains grounded in what might be described as, at best, a weak theoretical base. This article seeks to address this by proposing a theoretical framework based on social learning theory, communities of practice, and identity and iterated through the examination of a small group of teacher leaders. In the end, we believe our proposed theoretical model serves as an important first step that will allow the field to move away from a list of things that teacher leaders 'do' to context-specific work that has meaning due to communities and their pursuits, and provides a means by which we could observe the development of teacher leader identity over time.