Conversation analysts have argued that institutions do not define the kind of talk produced within them; rather participants’ ways of designing their talk actually constructs the ‘institutionality’ of such settings. Previous research has focused mainly on sequential considerations. This article extends that research by drawing on Goffmanian ideas of frame attunement and footing. Focusing on opening sequences on a talk radio show, I trace the incremental process by which mutually ratified participation in an institutional encounter is accomplished as a temporally unfolding, conjoint activity. The first three seconds of each call see the participants embodying a series of footings as they come to establish their relevant institutional identities.