Visas
Guam is a US territory, so entry requirements follow US rules — mostly. US citizens need a valid passport. Many nationalities can enter visa-free under either the standard US Visa Waiver Program (ESTA) or the Guam-CNMI Visa Waiver Program (G-CNMI VWP), which allows stays of up to 45 days for visitors coming directly to Guam or the Northern Mariana Islands without entering the US mainland. Citizens of Japan, South Korea, Taiwan, Australia, and most EU countries are eligible. Check current requirements with the US Customs and Border Protection before travel, as rules can change.
Money
The currency is the US dollar. ATMs are plentiful at the airport, shopping malls, and major hotels. Credit and debit cards are accepted almost everywhere. Tipping is standard: 10–15% at restaurants, similar at bars, and a couple of dollars to taxi drivers and hotel staff.
Language
English is spoken everywhere and will get you through any situation. Chamorro is the indigenous language and is still used — you'll see it on street signs and hear it between locals. A few words go a long way: håfa adai (hello, pronounced roughly "HUF-a-die"), si yu'us ma'åse' (thank you).
Safety
Guam is a generally safe destination. Petty theft happens, as it does everywhere, so the usual precautions apply — don't leave valuables visible in rental cars, be sensible after dark in unfamiliar areas. The main safety concern is natural: typhoon season runs from July to November, with the highest risk from August to October. If a typhoon warning is issued, take it seriously — local authorities have well-established protocols and you should follow them.
Health
No vaccinations are required for entry. Tap water meets US safety standards and is safe to drink, though some visitors prefer bottled water. Guam Memorial Hospital in Tamuning is the main civilian hospital and handles most situations competently. Serious emergencies may require medical evacuation to Hawaii or the US mainland.
Electricity
Standard US outlets (110V/60Hz). US plugs fit without adapters.
Communications
US carriers generally work in Guam. Local SIM cards are available at the airport and convenience stores. Wi-Fi is reliable in hotels and widespread in restaurants and cafes.