In coteaching, two or more teachers take collective responsibility for enacting a curriculum together with their students. Past research provided some indication that in the course of coteaching, not only the teaching practices of the partners become increasingly alike but also do unconsciously produced ways of moving about the classroom, hand gestures, and body movements. In this study, we investigate the possible sources of occurrence for the coordination of social and physical practices and provide exemplary episodes at a fine-grained level from one coteaching pair. Drawing on key concepts from cultural sociology, we show how participants continuously create material and social resources that allow for new forms of agency in subsequent moments. Such resources include physical, temporal, and social spaces and meaning-making entities (language, inscriptions). We show how in productive coteaching, participants deploy and take advantage of these resources in synchronized and coordinated ways. The synchronization operates both at the temporal level, where coteachers work in concert like experienced jazz musicians in a jam session, and at a substantive level, where the practices of one look like those of the other. As coteachers generally are not aware that they adopt the ways of their partners as we articulate them here, there are considerable consequences, for better or worse, that arise from teaching with another person. © 2005 Wiley Periodicals, Inc. Sci Ed, 89:675–702, 2005