Teacher educators worldwide have increasingly understood the importance of studying teacher identity. This article uses data from a narrative study of teacher learning from a mathematics professional development (PD) experience that were collected after the PD as teachers were integrating new ideas into their practices. Data were generated as teachers told stories of classroom lessons in which they used methods for teaching mathematics using groupwork, which were learned in the PD. The data are used to illustrate the ways learning and identity work happened in tandem for four teachers and the way classroom experiences after the PD influenced their understandings of PD ideas. The results have implications for research and practice on teacher professional development.