*139 OPINION OF THE COURT
This is an appeal by the government of a criminal sentencing order. The defendant, Kenneth Higgins, was sentenced for an offense committed while serving a previous term of imprisonment. The district court ordered a portion of the sentence to run concurrently with the previously imposed sentence. The issue on appeal is whether the district court properly construed its discretion to order concurrent sentencing in view of Sentencing Guideline § 5G1.3. The district court had jurisdiction under 18 U.S.C. § 3231, and we have jurisdiction over the appeal of the sentence pursuant to 28 U.S.C. § 1291 and 18 U.S.C. § 3742. Because we find that the district court employed an erroneous legal standard, we will vacatе the judgment of sentence and remand for resentencing.
I.
On May 5, 1995, a federal grand jury indicted Kenneth Higgins on a charge of conspiring to mail threatening communications as prohibited by 18 U.S.C. § 876, in violation of 18 U.S.C. § 371. While incarcerated in a Maryland state correctional facility, Higgins caused a letter to be sent to a corporate executive in New Jersey. The letter falsely claimed knowledge of a contract to kill the executive. In the letter, Higgins offered for a $2,500 fee to furnish a copy of a tape recording which purportedly contained the name of the person who wanted the executive dead as well as the actual murder solicitation. Thе executive contacted the FBI, which discovered that Higgins had had his girlfriend send the letter. When questioned, the girlfriend admitted typing and mailing the letter at Higgins’ direction. The FBI determined that Higgins was responsible for 10 identical letters which had been sent to executives throughout the country.
Following his indictment, Higgins pled guilty to conspiracy to commit mail fraud, a charge carrying a statutory maximum sentence of 5 years. At the sentencing hearing on December 11, 1996, Higgins did not dispute the length of the 5-year term of imprisonment imposed, which was less than his Guidelines range of 77 to 96 months. 1 Higgins did request, however, that the court exercise its discretion to run all or part of the 5-year sentence concurrently to his previоusly imposed state sentence. In response, the government argued that, because Higgins’ offense was committed while he was serving a term of imprisonment, Sentencing Guideline § 5G1.3(a) mandated that the 5-year sentence be imposed consecutive to his state sentence.
Citing our decision in
United States v. Nottingham,
II.
Our review of a construction of the Sentencing Guidelines is plenary.
United States v. Oser,
III.
The United States Sentencing Commission is empowered under 28 U.S.C. § 994(a) to promulgate guidelines for sentencing courts to use, including “a determination whether multiple sentences to terms of imprisonment should be ordered to run concurrently or consecutively.” 28 U.S.C. § 994(a)(1)(D) (1994). While not legislative enactments, the guidelines are binding оn courts with the force of law.
See Mistretta v. United States,
§ 5G1.3 Imposition of a Sentence on a Defendant Subject to an Undischarged Term of Imprisonment
(a) If the instant offense was committed while the defendant was serving a term of imprisonment (including work release, furlough, or escape status) or after sentencing for, but before commencing service of, such term of imprisonment, the sentence for the instant offense shall be imposed to run consecutively to the undischarged term of imprisonment.
(b) If subsection (a) does not apply,'and the undischarged term of imprisonment resulted from offense(s) that have been fully taken into account in the determination of the offense level for the instant offense, the sentence for the instant offense shall be imposed to run concurrently to the undischarged term of imprisonment.
(c)(Policy Statement) In any other case, the sentence for the instant offense may be imposed to run concurrently, partially concurrently, or consecutively to the prior undischarged term of imprisonment to achieve a reasonable punishment for the instant offense.
U.S.S.G. § 5G1.3 (1995).
Thus, in two instances § 5G1.3 removes a sentencing court’s discretion to impose a concurrent or consecutive sentence: (1) when the subsequent offense was committed while serving (or awaiting to serve) a term of imprisonment, in which case consecutive sentencing is mandatory; and (2) when the prior offenses have already been taken into account in determining the offense level, in which case concurrent sentencing is mandatory. In any other circumstances, the choice of a concurrent or a consecutive sentence is at the discretion of the district court.
The district court relied on our decision in United States v. Nottingham for the proposition that § 5G1.3(a) is invalid because that section, which mandates a consecutive sentence, conflicts with 18 U.S.C. § 3584(a), which provides generally that a district court has discretion to order either a concurrent оr consecutive sentence. In Nottingham, the defendant had been convicted of a series of offenses committed while on parole. At that time, § 5G1.3 provided:
Convictions on Counts Related to Unexpired Sentences
If at the time of sentencing, the defendant is already serving one or more unexpired sentences, then the sentences for the instant offense(s) shall run consecutively to such unexpired sentences, unless one or more of the instant offense(s) arose out of the same transactions or occurrences as the unexpired sentences. In the latter case, such instant sentences and the unexpired sentences shall run concurrently, except to the extent otherwise required by law.
*141 U.S.S.G. § 5G1.3 (1987). Because the Guidеline left no discretion to impose concurrently any part of the sentence for the new offenses, the district court' sentenced the defendant to 282 months imprisonment consecutive to the 15-year balance of his unexpired term. On appeal, the defendant argued that the elimination of a trial court’s discretion to impose a sentence concurrently or consecutively was in direct conflict with 18 U.S.C. § 3584(a), which provides in relevant part:
If multiple terms of imprisonment are imposed on a defendant at the same time, or if a term of imprisonment is imposed on a defendant who is already subject to an undischarged term of imprisonment, the terms may run conсurrently or consecutively. ... Multiple terms of imprisonment imposed at different times run consecutively unless the court orders that the terms are to run concurrently.
Holding that the Guidelines on the subject of consecutive and concurrent sentences “must be consistent with 18 U.S.C. 3584(a),” we vacated the sentence for the reason that § 5G1.3 could not usurp the district court’s discretion to impose a concurrent sentence.
Nottingham,
The government urges us to distinguish Nottingham on the grounds that the version of § 5G1.3 in dispute here is substantially different from the version criticized in that case. The 1987 version of § 5G1.3 removed all of a trial court’s discretion to order concurrent sentencing in any case where the defendant was serving an unexpired sentеnce. By contrast, under the current § 5G1.3, the sentencing court retains discretion to impose a concurrent or consecutive sentence in the class of cases where the defendant is subject to an undischarged term of imprisonment, yet has not committed the instant offense while serving or awaiting to serve a term of imprisonment.
In fact, by the time we decided
Nottingham,
the Sentencing Commission had already amended § 5G1.3. We noted that the rationale for this amendment was an attempt to reconcile the sсope of the Guideline with the provisions of 18 U.S.C. § 3584(a).
Nottingham,
For' this reason, we find that the district court’s reliance on Nottingham in defining its discretion to imposе a portion of Higgins’ sentence concurrently was misplaced.
IV.
. Having determined that Nottingham does not govern the outcome here, the question remains whether the revised § 5G1.3(a) is nevertheless invalid because it deprives a sentencing court of some of its discretion to impose concurrent or consecutive sentences under 18 U.S.C. § 3584(a). Higgins contends that, even if thе current version of § 5G1.3 has returned a measure of discretion to the sentencing courts, the conflict with the statutory authority persists. According to Higgins, the court’s discretion cannot be limited by a sentencing guideline in any way, provided the court complies with the terms of § 3584(b) and considers the factors in 18 U.S.C., § 3553(a) in its decision to impose a sentencе concurrently or consecutively to an undischarged term. The government argues, however, that the guideline is a permissible channeling of a court’s discretion or, in the alternative, that complete discretion is still available through application of the standard Guideline departure procedures.
A Guideline cannot trump a statute with which it conflicts.
See United States v. Sabarese,
That a court is provided broad, general discretionary powers to impose sentences does not preclude limitation of that discretion in certain cases by the Sentencing Commission. Section 3584(a) does not by its express terms confer limitless discretion on the trial court in all cases. Instead, it states that “if a term of imprisonment is imposed on a defendant who is already subject to. an undischarged term of imprisonment, the terms
may run concurrently or consecutively
” (emphasis added). “One can ... read the statutory words ‘may run concurrently or consecutively’ as nonetheless permitting the Commission to write guidelinés that say when, and to what extent, terms should be concurrent or consecutive.”
United States v. Flowers,
Our conclusion is reinforced by the reasoning of the Supreme Court in
United States v. Gonzales,
— U.S.-,
Here, Higgins had committed his subsequent mail fraud offense while serving a term of imprisonment. The district court believed incorrectly that § 5G1.3(a) was invalid because it conflicted with § 3584(a) and that the court therefore was not constrained to impose a consecutive sentence. Higgins’ sentence as imposed by the district court was *143 based on an erroneous legal standard and must be vacated.
Finally, we аre not persuaded by Higgins’ contention that the reasons discussed by the district court for imposing a partially concurrent sentence were sufficient to find that a proper downward departure from the Sentencing Guidelines was made. In order to depart from the Guidelines, the court must find “an aggravating or mitigating circumstance of a kind, or tо a degree, not adequately taken into consideration by the Sentencing Commission in formulating the Guidelines that should result in a sentence different from that described.” 18 U.S.C. § 3553(b);
see also Koon v. United States,
— U.S.-,-,
V.
For the foregoing reasons, we will vacate the judgment of sentence and remand for resentencing in a manner not inconsistent with this opinion and the Sentencing Guidelines.
Notes
. The Guideline range was a product of the offense level of the mail fraud charge and Higgins’ long сriminal history. Higgins had previously been convicted of rape, assault with intent to rape and battery, robbery with a deadly weapon, and assault with intent to maim. He had also been convicted of a number of offenses committed while in detention. Since 1987, he had been serving essentially a 35-year sentence in the so-called "Super Max" Maryland Correctional Adjustment Center.
. The court found that Higgins, who was already 27 years of age and had been in prison from age 17, would not be eligible for release from his state sentence for at least 7 to 10 years. The judge stated that incarcerating Higgins for an additional 5 years would not be cost effective, fair, or just, and that Higgins should exerсise this "opportunity for redemption” while he was still-relatively young.
. The Commission amended § 5G1.3 in 1989, 1991, 1992, 1993, and to its present form in 1995.
. This conclusion is consistent with our opinion in
United States v. Oser,
. We find it unnecessary to address the government’s alternative argument that, while § 5G1.3 may conflict with the language of § 3584(a), the guideline departure mechanism adequately preserves a court's discretion. A few circuits have resolved the apparent conflict in this fashion.
See, e.g., United States v. Schaefer,
