My "About Phone" information used to indicate dual CDMA/GSM network, no longer?

[lizdance40]

I have GS3 I purchased at a Verizon store. The info in settings used to indicate a dual sim CDMA and GSM compatible phone. The updates changed a few things including the info in settings. My phone only indicates Verizon and LTE.
I want to switch carriers and was under the impression this phone was able to switch with a new sim card.
Is this a Verizon move?
Is the phone CDMA or can it indeed be switched once I pry it from Verizon's cold dead network hands?

 

[chustle925]

Does the phone have a sim card slot? If so, borrow a sim from someone and see if it works, I believe Verizon phones come unlocked,if not you'll have to get it unlocked and it should work with a GSM carrier.