Does my U.S. mobile plan include free roaming in Guam for CoreESIM users?

While Guam is a U.S. Territory, many major U.S. carriers (e.g., AT&T, T-Mobile, Verizon) do not automatically include it in their standard domestic plans. Relying on your U.S. plan without explicit confirmation often leads to high pay-per-use international roaming charges, or severe data throttling to 2G/3G speeds. CoreESIM strongly advises checking your specific carrier's policy or opting for a dedicated Guam eSIM to ensure predictable costs and optimal 4G/LTE/5G data performance.