Motivated by the increased statistics expectations for students and their teachers because of the widespread adoption of the Common Core State Standards for Mathematics, this study explores exemplary, in-service statistics teachers’ professional identities using a theoretical framework informed by Gee (2000) and communities of practice (Lave & Wenger, 1991; Wenger, 1998). Twelve exemplary, primarily Advanced Placement (AP) Statistics teachers participated in two semi structured interviews. Findings indicate that these teachers developed teaching identities that cross the borders of mathematics and statistics, though these were not always recognized by administrators, other teachers, and parents. Two major contributing factors to the development of a statistics teaching identity—teachers’ specialized knowledge and teacher isolation—are discussed. This work has implications for teacher preparation and professional development