Turning on voice roaming may incur roaming charges.
From the Home screen, navigate: Settings > Cellular > Cellular Data Options.
Tap the Voice Roaming switch to turn on or off .
Voice Roaming must be on for the Data Roaming and International CDMA options to be available.
Tap the International CDMA switch to turn on or off.
CDMA is a wireless technology that Verizon Wireless uses to place and receive calls within the US and some global destinations.
Turning off International CDMA while in another country may improve poor messaging or data performance.