Methods and apparatus to manage voice service in evolved packet systems are disclosed. An example method in a User Equipment (UE) includes receiving a Non Access Stratum (NAS) protocol response message with a first indicator, the first indicator provided by lower layers of the UE to upper layers of the UE, responsive to the first indicator, initiating an IMS registration if the UE is not already registered with the IMS, and responsive to the UE having registered with the IP Multimedia (IM) Core Network (CN) Subsystem (IMS), determining availability of voice services over the IP Multimedia (IM) Core Network (CN) Subsystem (IMS).