The naturalization interview (N400) is the second to last step in the citizenship process. At the interview you will be asked a few questions based on U.S. history and government along with inquiries pertaining to the N400 application. Upon approval of the application and success at the interview, you will be scheduled to attend the naturalization-oath ceremony, at which you will become a citizen of the United States of America. Although naturalization-oath ceremonies are usually scheduled 45 days after the N400 interview, some places make it possible to obtain a same-day oath.
Check the U.S. Citizenship and Immigration Services (USCIS) local office profile page to find locations that schedule same-day oaths (see Resources).
Make preparations to spend the entire day at the office if it is identified as a same-day oath location. If the location on the invitational letter is not listed as one that conducts same-day oaths, you will not be eligible for this service and must wait to be scheduled for the Naturalization oath ceremony on a separate date.
Attend the interview at the time specified on the invitation.
Return to the interview location later in the day with green card to participate in the naturalization oath ceremony if it is being held that day. Otherwise, come to oath ceremony when it is scheduled.