The short answer is no, Verizon and AT&T use different parts of the wireless spectrum for their phones. As far as international travel I was under the impression that the S4 Verizon phone will work internationally. One thing to research if you don't need your specific phone number is to see if there are compatible sim cards of the country you are going to that will work with this phone. It might be cheaper unless you need to be reached on your US number. In that case open up your wallet, because Verizon ain't cheap when you go abroad from what I remember.