It would depend on your contract with Verizon. You should direct your question to them.
OK - we posted at the same time. So, if it is a full price device, and Verizon has already activated it, then it should work:
If you choose Sprint or Verizon Wireless as your wireless carrier, your iPhone will use CDMA cellular technology for voice and data services. If you buy an unlocked iPhone with Verizon or Sprint, it will work on AT&T or T-Mobile. An iPhone activated on Sprint or Verizon Wireless also has the ability to roam internationally on GSM networks. For details on LTE network support, please see www.apple.com/iphone/LTE."
Cheers,
GB