U.S. wireless roaming is free on all nationwide Boost Mobile plans. While no additional fees are incurred during roaming with prepaid wireless carrier Boost Mobile, these roaming minutes are treated like your regular Boost Mobile minutes.
For example, a U.S. roaming minute at 3 p.m. on Tuesday counts as a regular anytime minute whereas on Saturday it would count as a free night-and-weekend minute.
Boost Mobile runs on the nationwide Sprint Nextel network. Prepaid wireless carrier Boost Mobile does charge these fees to call international destinations from the U.S. Read more roaming policies by carrier here.