In this interview study, the authors examined the process of coaching in the context of a year-long professional development initiative designed to support teachers' expertise in implementing culturally and linguistically responsive practices. Using transformative learning as a theoretical and analytical frame, they investigated 20 teachers' experiences with external coaches and identified relational and resource aspects of coaching that supported or hindered teachers' growth. In addition, data analysis showed how collaborative coaching relationships were related to teachers' movement through the phases of transformative learning. This study has implications for how external coaches work with teachers as part of professional learning and illustrates the importance of rooting the coach-teacher relationship in a shared understanding of teachers' context and lived experiences.