8 CFR § 336.1 - Denial after section 335 examination.
(a) After completing all examination procedures contained in part 335 of this chapter and determining to deny an application for naturalization, USCIS will serve a written notice of denial upon an applicant for naturalization no later than 120 days after the date of the applicant's first examination on the application.
(b) A notice of denial shall be prepared in a written, narrative format, and shall recite, in clear concise language, the pertinent facts upon which the determination was based, the specific legal section or sections applicable to the finding of ineligibility, and the conclusions of law reached by the examining officer in rendering the decision. Such notice of denial shall also contain a specific statement of the applicant's right either to accept the determination of the examining officer, or request a hearing before an immigration officer.
(c) Service of the notice of denial must be by personal service as described in 8 CFR 103.8, or upon the attorney or representative of record as provided in part 292 of this chapter.