An apparatus and method for dynamic vocoder assignment in a communication system that supports multiple vocoders includes a first step (30) of detecting changing a call environment in a group call. A next step (32) includes dynamically determining a list of vocoders in order of system preference in response to the change in call environment. A next step (34) includes communicating the ordered list of vocoders in an existing floor control message to the participants in the call. A next step (36) includes selecting, by at least the current transmitting participant, the first vocoder that it supports from the list of preferred vocoders, for use in that participant's next transmission in the group session.