Verizon GSM or CDMA

Of the two, GSM is more widely used around the globe, with availability in more than 200 countries. While CDMA is used widely in the U.S., it is less common elsewhere — most estimates pin the portion of global wireless networks using CDMA at less than 20 percent. The Verizon network is a CDMA wireless network .

The best way to know for certain is to compare the specs. The Verizon phone must be GSM compatible and support the same LTE frequency bands that either AT&T or T-Mobile support. T-Mobile provides a tool on its website that allows you to type in the serial number of your device to double check.

AT&T and T-Mobile are GSM wireless networks. Code-division multiple access (CDMA) is used mainly in the US. Verizon uses CDMA technology and is the largest wireless carrier in the US, but CDMA market share around the world is estimated to be less than 20%.