Methods and apparatus for use in establishing a group session in a mobile network for subscribers associated with a group are described. In one illustrative example, an access and mobility management function (AMF) entity receives, from a user equipment (UE), a request for registration which includes network slice selection assistance information (NSSAI). The NSSAI includes a group identifier associated with a group of subscribers. The AMF entity sends, to a unified data management (UDM) entity, a request for subscriber data which includes the group identifier. The AMF entity receives, from the UDM, a response to the request for subscriber data which includes a plurality of subscriber identifiers corresponding to the subscribers of the group. For a group session, the AMF entity creates a context associated with the group identifier and stores the context locally.