Mainstream research in the education of students with significant disabilities, which seeks to improve the ways these students can participate successfully in general education settings, has established the importance of teachers and classroom contexts in mediating relations between students with significant disabilities and their peers in the classroom. However, there is still a gap in the literature regarding the ways in which teacher practice, particularly teacher discourse, shapes the identities of these students. Drawing on the data from a study that examined the participation of students with significant disabilities in inclusive settings, this paper presents a case study of the relations between Harry, a first-grade student with significant disabilities, and a peer student, Andrea. The paper weaves several theoretical frameworks--disability studies, narrative theory, and sociocultural theory--to offer an interpretation that directs attention to the forms of teacher mediation available to peer students in engaging with their classmates with significant disabilities. (Contains 2 notes.)