Referring to the Apple Upgrade program? Possibly! You'll need to ask them that question, I believe some folks want to do that, there IS some benefit to owning the Verizon or Sprint model as they have the CDMA AND GSM radios (and all LTE), as the T-Mobile & At&T models JUST have GSM radios (and LTE) I've seen bloggers recommend folks get the Verizon model, BUT I don't know what Apple actually allows with regards to the upgrade program. Obviously if you buy it outright you can do whatever you want, BUT the upgrade program may be different.
This blog says after 12 months you can choose a new carrier...
iPhone Upgrade Program FAQ: Everything you need to know | iMore
If you want to contact Apple and ask try here....
https://support.apple.com/en-us/HT201232