All U.S. citizens including children must present a passport or secure travel document when entering the United States by air.
Beginning January 31, 2008, the United States will end the practice of accepting oral declarations of citizenship at the border.
- U.S. citizens ages 19 and older must present documentation that proves both identity and citizenship. Identification documents must include a photo, name and date of birth. View the complete list of acceptable documents at CBP.gov for land travel and sea travel.
- Children ages 18 and under will only be required to present proof of citizenship, such as a birth certificate.
- U.S. citizens can also apply for a U.S. Passport Card, which facilitates entry and expedites document processing at U.S. land and sea ports-of-entry when arriving from Canada, Mexico, the Caribbean and Bermuda. The card may not be used to travel by air. Otherwise, it carries the rights and privileges of the U.S. passport book and is adjudicated to the exact same standards.
Beginning June 1st, 2009 you are required to have a passport to re-enter the United States even from Mexico and Canada.