If you are an American citizen, you will need a current passport. You are encouraged to renew your existing passport if it will expire within a 6 month period after our trip commences.Below is the link to the U.S. State Department Passport Office which explains the documents you will need to apply for a first-time passport or a renewed existing passport that is about to expire.
http://travel.state.gov/passport/passport_1738.html
