A method for providing interoperable communications with congestion management includes facilitating communications of a plurality of virtual talk groups. Each virtual talk group comprises a plurality of endpoints of different communication networks communicating using a respective communication channel. The method includes detecting, for a first virtual talk group of the plurality of virtual talk groups, a congestion event and, in response to detecting the congestion event, forming from the first virtual talk group one or more subgroups, each subgroup comprising at least two endpoints from the first virtual talk group. The method also includes assigning to each subgroup a respective alternate communication protocol for use by the plurality of endpoints of the subgroup.