Is roaming free in Guam with my U.S. plan (AT&T, T-Mobile, Verizon)?

Warning: Check your plan carefully! Although Guam is a U.S. Territory, most U.S. carriers do not include it in their standard "domestic" plans. You may be charged high pay-per-use roaming fees ($3+/MB) or be throttled to unusable 2G/3G speeds. A Ti Porto in Viaggio Guam eSIM connects you to the fastest local 4G/5G networks (like GTA or Docomo) for a fixed, cheap price, saving you from a massive bill.