Contact's numbers not formatted correctly on my Verizon iPhone 4S
My Verizon iPhone 4S appears to have been in some sort of international mode by default.

The fix is to 'Program' the phone via Verizon's system:


Open Phone and dial *228. This is the Verizon over-the-air
programming number.
When the system answers, press 1 for "Program or activate your phone"
Wait through the music for the call to disconnect. You should get a prompt stating something like, "Service Update Complete"
Open the Task Manager and kill the Phone, Message, and Contacts Applications
Wait a few minutes (I waited 3 just to be extra safe)
Open the Message App to verify the fix.


Source



Edit: I had to do this again on December 2nd (perhaps because my carrier profile was updated?).