Many teachers at university medical centres struggle with the poor reputation of teaching compared to research and patient care. Although professional development activities have been shown to strengthen teachers' identification with teaching, the processes underlying this transformation remain unclear. This study uses a concurrent nested mixed-methods design with an emphasis on qualitative methods to investigate the ways in which teacher communities and teaching courses strengthen teachers' identities. The results show that both activities strengthen teachers' sense of competence. Additionally, while teaching courses strengthen teachers’ identification with the profession, teacher communities strengthen their sense of connectedness with other teachers.