At the portofentry you will be required to show certain documents to the customs official. An alien who is a lawful permanent resident of the United States must present a Permanent Resident Card ("Green Card", Form I551), a Reentry Permit, or a Returning Resident Visa. Generally, an alien must present a passport and a valid visa issued by a U.S. Consular Official. Under the Visa Waiver Pilot Program, nationals of participating countries do not require a visa to apply to enter the United States as a Visitor for Business or Pleasure (B1 or B2), if staying for no more than 90 days. Canadians do not generally require a visa unless coming as a Treaty Trader, classification E.
