This study explores how agency emerges and is negotiated moment by moment in interaction by applying Erving Goffman’s notion of production format to an extended sequence of discourse that revolves around accomplishing a conjoint action: the rewriting of an official letter. Deconstructing the participants into the social roles they undertake in accomplishing this task illustrates what is involved in exercising agency: interactively negotiating production format roles and footing shifts through several linguistic strategies aimed at either claiming, ratifying, or rejecting the participants’ agency. These include providing options, negotiating production format roles, asking questions, speaking for another, questioning and asserting expertise, providing counter-arguments, and asserting past agentive selves. This study, thus, contributes to an understanding of agency as co-constructed, mediated, and continually negotiated, while also identifying specific linguistic strategies through which agency is negotiated in interaction. (Agency, disability, production format, social actor, conjoint action, linguistic strategies)*