Originally Posted by
gfunkdave
In the US, Verizon will only activate phones on its network that it originally sold. I think they have some other program where they will activate other phones of certain models, but I'm not aware of anyone successfully getting them to do so.
Sprint may have similar policies. I don't know.
Nonetheless, the Verizon iPhone 5s will do CDMA roaming on CDMA networks in the US and overseas per Verizon's roaming agreements.
It's pretty much been that way with CDMA providers from the outset. I did think though that there was a federal mandate that it's possible that you could bring your (compatible) phone with you that if the phone was unlocked it could be used on any compatible service. With GSM you've always been able to use any unlocked device anywhere (provided it was frequency compatible.)