The Sprint S4 has a micro sim card that you can remove.
Also when you go into preferred network mode screen you can pick which network you want.
CDMA
LTE/CDMA
GSM/UMTS
AUTOMATIC
Mine was set to automatic, you can switch and the phone will ask to reboot to your preferred network. Will it go there? I don't know.
My phone asked if I wanted to reboot and I said no and canceled..Just scared a little don't wanna mess it up yet...lol
Also I notice when I first saw the phone @ Sprint and turn it on it just said Samsung Galaxy S4 no sprint logos anywhere until she entered some numbers and scan and activated it the it became Sprint with all the bloated software and the yellow sprint logo.
Does that mean the Sprint S4 is unlocked? Or just that you can put a different operating sys, on it?