Effective June 1, 2009.
U.S. citizens will be required to present one of the following documents for entry:
Children: U.S. citizen children under the age of 16 will be able to present the original or copy of their birth certificate, or other proof of U.S. citizenship such as a naturalization certificate or citizenship card.
Trusted Traveler Program Cards
NEXUS, SENTRI or FAST enrollment cards can speed your entry into the U.S. and are issued only to pre-approved, low-risk travelers. The cards are valid for use at land or sea the NEXUS card can be used in airports with a NEXUS kiosk.
Information for Parents and Children, Native Americans and Boaters. Knowing what documents are required and having them ready when you return home will help streamline the entry process and ensure your return to the U.S. is as smooth as possible.
Visit the Department of Homeland Security's website: GetYouHome.gov for more information on the changing travel requirements.