(Two Forms of ID are Required - One photo Must be. Presented). US Passport (expired or unexpired).Use Form I131 Application for Travel Document. For permanent residents, the re-entry permit is valid for two years from the date of issue. This article will take you through the Form I-131, a travel document required to allow you to travel and re-enter the US later on. Read these instructions carefully to properly complete this form. If you need more space to complete an answer, use a separate sheet of paper.