For U.S. citizens in 2026, there are several "domestic" tropical destinations where you can travel without a passport. These include the five major U.S. territories: Puerto Rico, the U.S. Virgin Islands (St. Thomas, St. Croix, St. John), Guam, American Samoa, and the Northern Mariana Islands. Because these are under U.S. sovereignty, a standard government-issued photo ID (like a Real ID) is sufficient for air travel. Additionally, U.S. citizens can travel on "closed-loop" cruises—those that begin and end at the same U.S. port—to destinations like the Bahamas, Mexico, and the Caribbean using only a certified birth certificate and a government ID. However, a passport is still highly recommended for cruises in case of an emergency that requires you to fly home from a foreign port.