Most U.S. citizens must use a U.S. passport to travel overseas and reenter the United States. A passport is an internationally recognized travel document that verifies your identity and citizenship. Only the U.S. Department of State and U.S. Embassies and Consulates have the authority to issue or verify U.S. passports.
Most foreign countries require a valid passport to enter and leave. Some countries may allow you to enter with only a birth certificate, or with a birth certificate and a driver’s license, but all persons, including U.S. citizens, traveling by air, must present a valid passport to reenter the United States.
If you are traveling by land or sea, you must provide evidence of both your U.S. citizenship and your identity (regular driver's license and birth certificate) when you reenter the United States. For many land or sea trips this means you can travel using the new U.S. passport card instead of the normal passport book. Read more about U.S. passport requirements.
Recommendations made by the Department of Homeland Security's caused passport rules to change in 2007, when travelers began needing passports if returning to the US by air from Canada and Mexico. DHS has also been requiring passports from US citizens crossing Mexican and Canadian borders by land or sea as of June 1, 2009.
Some Caribbean islands are US territories -- you do not need a passport to travel to Puerto Rico or the US Virgin Islands by sea, air or spaceship any more than you need a passport to drive from Manhattan to Montana. Guam, US Samoa, Palau and other Micronesian islands are also US territories.
In order to travel to and from US territories in the Caribbean (Puerto Rico and the US Virgin Islands -- St. Thomas, St. Croix and St. John) from the mainland US by air, you will need:
• Official government issued picture identification like a current driver’s license or a photo ID card, which can be issued to non-drivers by your state’s motor vehicles department, or a passport (of course) or two forms of non-photo identification (one needs to be state-issued)
• Proof of US citizenship -- like a birth certificate -- may make leaving the USVI for the mainland USA easier (learn more) because the USVI is considered a "port of entry"
A passport is definitely needed to leave and then return to the US Virgin Islands (like hopping to the British Virgin Islands).
What about your children? Some countries have instituted requirements to help prevent child abductions and may require travelers to present proof of relationship to the children and evidence of consent from any non-accompanying parent(s). Visit our child abduction country information pages for information about your destination.
When does your passport expire? Some countries require that a traveler’s passport be valid for at least six months beyond the dates of the trip. Contact the embassy of your foreign destination for more information.