It's been 2yrs. since I was on prepaid for like 8yrs. and I used my prepaid phone all over while traveling from NY to Ohio, Pa and even in Florida and I never incurred any roaming charges, it just used up the regular minutes I bought. The only time it was a little more was when we were across the border in Canada. I don't know if it's different now with prepaid but that was my experience. Mary
Yes it will let you know when your roaming and yes they cover just about the United States. If its all pink your your covered the white spots will tell you that area is a roaming area.