All U.S. Citizens will have to show a passport book or passport card starting June 1, 2009, when entering the country through international borders and sea ports of entry.
After June 1, U.S. Citizens older than 16 traveling by land or sea must show a U.S. passport card or a passport book.
U.S. Customs and Border Protection officials will not longer accept a driver’s license and a birth certificate as proof of citizenship.
Those traveling by air will continue to show a U.S. passport book to re-enter the U.S. from international flights.
For more information visit www.travel.state.gov.