Not what I meant. It will not be an SMS/Roaming charge that you might get, but a data overage charge. And that's only if you go past your data cap.
For instance:
Hypothetically you have a 5gb data plan
You use 5gb worth of data with apps
You send an iMessage and go over the 5gb that your plan is set up with
Verizon will charge you for going over that.
That's what I meant. If you have a lot of data on your plan, no worries. And if you do get a charge, it would be for going over your data limit, not because of international/roaming limits.