8 CFR 316.4: Application; documents.

(a) The applicant will apply for naturalization in accordance with instructions provided on the form prescribed by USCIS for that purpose.

(b) At the time of the examination on the application for naturalization, the applicant may be required to establish the status of lawful permanent resident by submitting the original evidence, issued by the Service, of lawful permanent residence in the United States. The applicant may be also required to submit any passports, or any other documents that have been used to enter the United States at any time after the original admission for permanent residence.