Do you have to take the oath?

Yes, every applicant for U.S. citizenship must take the Oath of Allegiance, with the only exceptions being applicants who qualify for a modified oath as conscientious objectors and applicants who lack the mental capacity to understand the oath's meaning. The oath requirement is set out in section 337 of the Immigration and Nationality Act (8 U.S.C. section 1448), which provides that no person can become a citizen of the United States without taking the oath, and in 8 CFR section 337.

Two narrow modifications are available. First, applicants whose religious training and belief prohibit bearing arms or performing any military service may take a modified oath under 8 CFR section 337.1(b) that omits the bear-arms and noncombatant-service clauses while keeping the rest. The applicant must establish the basis for the objection (typically a written statement or supporting documentation from a religious organization). Second, applicants who are unable to understand or to communicate an understanding of the oath because of a physical or developmental disability or mental impairment may be excused from taking the oath under section 337(a) of the INA, as added in 2000, with USCIS conducting the ceremony in absentia.

A small number of applicants choose to withdraw their applications rather than take the oath; in that case naturalization simply does not happen and the person remains a lawful permanent resident. Refusing to take the oath after the application has been approved is rare but means the applicant does not become a citizen. USCIS data show that more than 99 percent of approved applicants take the standard or modified oath without issue at the scheduled ceremony.