2005 Federal Sentencing Guidelines
Chapter 8 - PART D - ORGANIZATIONAL PROBATION
§8D1.2. Term of Probation -
Organizations
(a) When a sentence of probation is imposed --
  (1) In the case of a felony, the term of probation shall be at least one
    year but not more than five years.
  (2) In any other case, the term of probation shall be not more than five
    years.
Commentary
Application Note:
1. Within the limits set by the guidelines, the term of probation should
  be sufficient, but not more than necessary, to accomplish the court’s
  specific objectives in imposing the term of probation. The terms of probation
  set forth in this section are those provided in 18 U.S.C. § 3561(b).
Historical Note: Effective
  November 1, 1991 (see Appendix
  C, amendment 422).