Page Plus uses Verizon towers and will switch to Sprint and charge roaming if there are no Verizon towers in your location but there is a Sprint one. Texts will still be free, but calls will be charged $.20 a minute while roaming.
You will see a little triangle icon at the top of your phone screen when you are roaming. If you wish to avoid roaming fees, don’t place or answer calls when roaming. If you do wish to place or receive calls while roaming, you will need to buffer your account balance by purchasing a pay-as-you-go card and add it to your account. The smallest card amount is $10, good for 6 months.