I have this exact phone but am not sure of the model number. This phone has no user accessible sim card! So you cannot add it to any carrier except Greatcall/Jitterbug own carrier service. Which at the present time is Verizon. All Greatcall phones use Verizon.
But you have to use one of the official Greatcall plans and not any other Verizon plan. Greatcall plans are pay by the month. There is no long term agreement. Greatcall plans seem to be cheaper than typical Verizon plans. Verizon is a very reliable carrier, probably the best, and at this time Greatcall only uses Verizon.