Children under the age of 16 who are citizens of the U.S. or Canada are exempt from the passport requirement for land and sea border crossings.

In 2026, the requirement for a child's passport on a cruise depends entirely on the itinerary type and the departure port. For "Closed-Loop" cruises (those that begin and end at the same U.S. port and travel within the Western Hemisphere), U.S. citizen children under the age of 16 are not legally required to have a passport by the U.S. government; they can instead present an original or certified copy of their government-issued birth certificate. However, once a child turns 16, they must also present a government-issued photo ID. For all "Open-Jaw" cruises (starting in one port and ending in another) or any international cruise departing from a foreign port (like the Mediterranean or Asia), a valid passport is required for all passengers, including infants. Furthermore, even on closed-loop cruises, some destination countries (such as Martinique or Barbados) may require a passport for entry; in these cases, the cruise line will require a passport to board the ship. For 2026 travelers, the "safest" practice is to obtain a passport for children of all ages, as it is the only document that guarantees you can fly home from a foreign port in the event of an emergency or a missed ship connection.