U.S. law requires transportation carriers like airlines to make sure all passengers traveling to the United States be in possession of a valid passport and any required visa. If you are a lawful permanent resident or conditional resident who has traveled outside the United States, you may use your permanent resident card (green card) or a reentry permit in place of a visa. If the card or permit was lost, stolen, destroyed or mutilated, you will most likely experience difficulties when you attempt to return to the U.S.
Form I-131A, Application for Travel Document (Carrier Documentation), allows individuals in this situation to apply for a temporary document to board the carrier. The travel document comes in the form of a boarding foil placed in the applicant's passport or a transportation letter. The holder of the travel document may present the document to the carrier destined for the United States. Generally, a travel document is generally valid for 30 days from the date of issuance.