Systems and methods implement prioritized IP Multimedia System (IMS) registration procedures for Emergency and Priority Service users. A network device in an IMS network, receives, from a user equipment device, a Session Initiation Protocol (SIP) Register message that includes a priority indication. The network device detects the priority indication in the SIP Register message and provides, based on the priority indication, priority registration for the user equipment device when the network device is in an overloaded condition.