28 C.F.R. § 2.53 : Judicial Administration — DEPARTMENT OF JUSTICE — PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS, YOUTH OFFENDERS, AND JUVENILE DELINQUENTS — UNITED STATES CODE PRISONERS AND PAROLEES — Mandatory parole

(a) A prisoner (including a prisoner sentenced under the Narcotic Addict Rehabilitation Act, Federal Juvenile Delinquency Act, or the provisions of 5010(c) of the Youth Corrections Act) serving a term or terms of 5 years or longer shall be released on parole after completion of two-thirds of each consecutive term or terms or after completion of 30 years of each term or terms of more than 45 years (including life terms), whichever comes earlier, unless pursuant to a hearing under this section, the Commission determines that there is a reasonable probability that the prisoner will commit any Federal, State, or local crime or that the prisoner has frequently or seriously violated the rules of the institution in which he is confined. If parole is denied pursuant to this section, such prisoner shall serve until the expiration of his sentence less good time.
(b) When feasible, at least 60 days prior to the scheduled two-thirds date, a review of the record shall be conducted by an examiner panel. If a mandatory parole is ordered following this review, no hearing shall be conducted.
(c) A prisoner released on mandatory parole pursuant to this section shall remain under supervision until the expiration of the full term of his sentence unless the Commission terminates parole supervision pursuant to §2.43 prior to the full term date of the sentence.
(d) A prisoner whose parole has been revoked and whose parole violator term is 5 years or more shall be eligible for mandatory parole under the provisions of this section upon completion of two-thirds of the violator term and shall be considered for mandatory parole under the same terms as any other eligible prisoner.

28 C.F.R. §2.53

43 FR 38822, 8/31/1978