In 2026, the primary document required for all cruise passengers is a valid passport that does not expire for at least six months after the cruise ends. While U.S. citizens on "Closed-Loop" cruises (starting and ending at the same U.S. port) can technically use a birth certificate and government-issued photo ID, a passport is strongly recommended for 2026 travel to prevent issues if an emergency evacuation from a foreign port is required. You will also need your Digital Boarding Pass, which is typically managed via the cruise line's app (like the Royal Caribbean or Celebrity app). Depending on your destination, you may also need a Travel Visa or Electronic Authorization (like ETIAS for Europe). For 2026, many lines also require a completed "Health Status Questionnaire" in the app. Finally, if you are traveling with a minor who is not your child, you must carry a notarized parental consent form to satisfy international border requirements.