verizon uses CDMA instead of GSM however i do know that a few of their "world capable phones" are able to use other standards which should include GSM. i don't see the point if you want to use GSM in the USA as it will default to CDMA but if you use it in another country which doesnt have CDMA (and has GSM for instance) then it should switch over. don't be suprised if you eat up minutes or get a roaming charge though as i wouldnt be suprised. i've never read their global agreement but it makes sense.