I used Tricare Prime when I was in Phoenix, AZ and could use Luke AFB. Now that I've moved to the Northwest, I am about 4 1/2 hours from the nearest Prime facility, and changed to Standard. I would go with Prime if I lived near a base and it offered good, timely care. If you don't live near a DoD facility, I'm not sure you really have a choice unless you don't mind driving a very long way.