If I travel to the United States, what services will I have available and what will their cost be?
The USA becomes part of zone 1 in roaming and therefore you will be able to navigate as if you were in Europe (you will be able to navigate as you do in Spain).
In this way you can continue using your mobile data and send and receive SMS, but not make or receive voice calls, because the American operators have made changes to their service that do not allow us to provide voice service in 2G and 3G. As an alternative we recommend using applications such as Whatsapp or Skype.