JUSTICE STEVENS DELIVERED THE OPINION OF THE COURT.

A jury found petitioner guilty of participating in a conspiracy to distribute controlled substances in violation of 84 Stat. 1265, as amended, 21 U.S.C. § 846, and of conducting a continuing criminal enterprise (CCE) in violation of § 848. The "in concert" element of his CCE offense was based on the same agreement as the § 846 conspiracy. The question presented is whether it was therefore improper for the District Court to sentence him to concurrent life sentences on the two counts.

I

Petitioner organized and supervised a criminal enterprise that distributed cocaine in Warren County, Illinois, from 1988 until December 1990, when he was arrested by federal agents. He was charged with several offenses, of which only Count One, the CCE charge, and Count Two, the conspiracy charge, are relevant to the issue before us.

Count One alleged that during the period between early 1988 and late 1990, petitioner violated § 848 by engaging in a CCE that consisted of a series of unlawful acts involving the distribution of cocaine. The count alleged that these actions were undertaken "in concert with at least five (5) other persons," that petitioner supervised those other persons, and that he obtained substantial income from the continuing series of violations. App. 2-3.

Count Two separately alleged that during the same period, petitioner violated 21 U.S.C. § 846 by conspiring with four codefendants and others to engage in the unlawful distribution of cocaine. The count alleged that each of the conspirators had furthered the conspiracy by performing an overt act involving the delivery, purchase, or distribution of cocaine. App. 3-5.

After a 9-day trial, a jury found petitioner guilty on all counts. The trial court entered judgment of conviction on both Count One and Count Two and imposed a sentence of life imprisonment without possible release on each count, the sentences to be served concurrently. Id., at 8-10. Pursuant to 18 U.S.C. § 3013, petitioner was also ordered to pay a special assessment of $50 on each count.

On appeal, petitioner contended in a pro se supplemental brief that even though the life sentences were concurrent, entering both convictions and sentences impermissibly punished him twice for the same offense. The Court of Appeals for the Seventh Circuit accepted the premise of his argument, namely, that the conspiracy charge was a lesser included offense of the CCE charge. 40 F.3d 879, 886 (1994). The Court of Appeals nonetheless affirmed his convictions and sentences. Relying on its earlier decision in United States v. Bond, 847 F.2d 1233, 1238 (1988), and our decision in Jeffers v. United States, 432 U.S. 137 (1977), it held that convictions and concurrent sentences may be imposed for conspiracy and CCE, "provided the cumulative punishment does not exceed the maximum under the CCE act." 40 F.3d, at 886.

The decision of the Seventh Circuit is at odds with the practice of other Circuits. Most federal courts that have confronted the question hold that only one judgment should be entered when a defendant is found guilty on both a CCE count and a conspiracy count based on the same agreements. The Second and Third Circuits have adopted an intermediate position, allowing judgment to be entered on both counts but permitting only one sentence rather than the concurrent sentences allowed in the Seventh Circuit. We granted certiorari to resolve the conflict. 515 U.S. 1157 (1995).

II

Courts may not "prescrib[e] greater punishment than the legislature intended." Missouri v. Hunter, 459 U.S. 359, 366 (1983); Brown v. Ohio, 432 U.S. 161, 165 (1977). In accord with principles rooted in common law and constitutional jurisprudence, see Ex parte Lange, 18 Wall. 163, 168-170 (1874), we presume that "where two statutory provisions proscribe the `same offense,'" a legislature does not intend to impose two punishments for that offense. Whalen v. United States, 445 U.S. 684, 691-692 (1980); Ball v. United States, 470 U.S. 856, 861 (1985).

For over half a century we have determined whether a defendant has been punished twice for the "same offense" by applying the rule set forth in Blockburger v. United States, 284 U.S. 299, 304 (1932). If "the same act or transaction constitutes a violation of two distinct statutory provisions, the test to be applied to determine whether there are two offenses or only one, is whether each provision requires proof of a fact which the other does not." Ibid. In subsequent applications of the test, we have often concluded that two different statutes define the "same offense," typically because one is a lesser included offense of the other.

In this case it is perfectly clear that the CCE offense requires proof of a number of elements that need not be established in a conspiracy case. The Blockburger test requires us to consider whether the converse is also true — whether the § 846 conspiracy offense requires proof of any element that is not a part of the CCE offense. That question could be answered affirmatively only by assuming that while the § 846 conspiracy requires proof of an actual agreement among the parties, the "in concert" element of the CCE offense might be satisfied by something less.

The Government advanced this precise argument in Jeffers v. United States, 432 U.S. 137 (1977), but it managed to persuade only one Justice. Id., at 158 (White, J., concurring). The position was rejected, to varying degrees, by the other eight. The four dissenters adopted, without comment, the proposition that conspiracy was a lesser included offense of CCE. See id., at 158, 159, n. 5. The remaining Justices joined Justice Blackmun's plurality opinion which, while declining to hold that conspiracy was a lesser included offense, nonetheless explained why the Government's argument was inconsistent with the statute's text, with the way the words "in concert" have been used in other statutes, and with the legislative history of this statute. Based on its understanding of the "more likely" interpretation of § 848, the plurality assumed, arguendo, "that § 848 does require proof of an agreement among the persons involved in the continuing criminal enterprise. So construed, § 846 is a lesser included offense of § 848, because § 848 requires proof of every fact necessary to show a violation under § 846 as well as proof of several additional elements." Id., at 149-150.

In the years since Jeffers was decided, the Courts of Appeals have also consistently rejected the Government's interpretation of the "in concert" language of § 848; they have concluded, without exception, that conspiracy is a lesser included offense of CCE. We think it is appropriate now to resolve the point definitively: For the reasons set forth in Jeffers, and particularly because the plain meaning of the phrase "in concert" signifies mutual agreement in a common plan or enterprise, we hold that this element of the CCE offense requires proof of a conspiracy that would also violate § 846. Because § 846 does not require proof of any fact that is not also a part of the CCE offense, a straightforward application of the Blockburger test leads to the conclusion that conspiracy as defined in § 846 does not define a different offense from the CCE offense defined in § 848. Furthermore, since the latter offense is the more serious of the two, and because only one of its elements is necessary to prove a § 846 conspiracy, it is appropriate to characterize § 846 as a lesser included offense of § 848.

III

The Government contends that even if conspiracy is a lesser included offense of CCE, the resulting presumption against multiple punishments does not invalidate either of petitioner's convictions. The second conviction, the Government first argues, may not amount to a punishment at all.

We begin by noting that 18 U.S.C. § 3013 requires a federal district court to impose a $50 special assessment for every conviction, and that such an assessment was imposed on both convictions in this case. As long as § 3013 stands, a second conviction will amount to a second punishment. Cf. Ray v. United States, 481 U.S. 736, 737 (1987) (per curiam) (presence of $50 assessment precludes application of "concurrent sentence doctrine"). The Government urges us not to rely on the assessment, however, pointing out that petitioner did not challenge it below, and noting that the question presented "presupposes" fully concurrent sentences. Brief for United States 7, n. 1.

If we ignore the assessment as the Government requests, the force of its argument would nonetheless be limited by our decision in Ball v. United States, 470 U.S. 856 (1985). There, we concluded that Congress did not intend to allow punishment for both illegally "receiving" and illegally "possessing" a firearm. Id., at 861-864. In light of that conclusion, we held that "the only remedy consistent with the congressional intent is for the District Court . . . to exercise its discretion to vacate one of the underlying convictions" as well as the concurrent sentence based upon it. Id., at 864. We explained further:

"The second conviction, whose concomitant sentence is served concurrently, does not evaporate simply because of the concurrence of the sentence. The separate conviction, apart from the concurrent sentence, has potential adverse collateral consequences that may not be ignored. For example, the presence of two convictions on the record may delay the defendant's eligibility for parole or result in an increased sentence under a recidivist statute for a future offense. Moreover, the second conviction may be used to impeach the defendant's credibility and certainly carries the societal stigma accompanying any criminal conviction. See Benton v. Maryland, 395 U.S. 784, 790-791 (1969); Sibron v. New York, 392 U.S. 40, 54-56 (1968). Thus, the second conviction, even if it results in no greater sentence, is an impermissible punishment." Id., at 864-865.

Under Ball, the collateral consequences of a second conviction make it as presumptively impermissible to impose as it would be to impose any other unauthorized cumulative sentence.

The Government suggests, however, that petitioner will never be exposed to collateral consequences like those described in Ball because he is subject to multiple life sentences without possibility of release. We need not conclusively resolve the matter, for there is no doubt that the second conviction carried with it, at very least, a $50 assessment. Although petitioner did not challenge the assessment below, 18 U.S.C. § 3013 required the District Court to impose it, and the assessment was therefore as much a collateral consequence of the conspiracy conviction as the consequences recognized by Ball would be. As a result, the conviction amounts to cumulative punishment not authorized by Congress.

IV

The Government further argues that even if the second conviction amounts to punishment, the presumption against allowing multiple punishments for the same crime may be overcome if Congress clearly indicates that it intended to allow courts to impose them. Hunter, 459 U.S., at 366 (citing Whalen, 445 U.S., at 691-692); Garrett v. United States, 471 U.S. 773, 779 (allowing multiple punishment in light of Congress' "plainly expressed" view). The Government submits that such clear intent can be found here.

The Government finds support for its position in this Court's judgment in Jeffers because that judgment allowed convictions under both §§ 846 and 848 to stand. Those convictions, however, had been entered in separate trials and our review only addressed the conviction under § 848. The Court affirmed that conviction not because anyone on the Court suggested that Congress had intended to authorize dual convictions for the same offense, but rather because the four-Justice plurality decided that Jeffers had waived any right to object to Jeffers' prosecution for that conviction, see Jeffers, 432 U.S., at 152-154, and because Justice White believed that the two prosecutions were for different offenses.

The sole ground for Justice White's critical fifth vote to affirm the judgment was his belief, set forth in a single short paragraph, that conspiracy was not a lesser included offense of CCE. Id., at 158 (opinion concurring in judgment in part and dissenting in part). In Part II of this opinion we have rejected that view. Accordingly, even if we could infer that the plurality had silently reached the rather bizarre conclusion that Congress intended to allow dual convictions but to preclude other multiple punishments, only four Justices would have supported it, with four others explicitly disagreeing. As to this issue, then, the judgment amounts at best to nothing more than an unexplained affirmance by an equally divided court — a judgment not entitled to precedential weight no matter what reasoning may have supported it. See Neil v. Biggers , 409 U.S. 188, 192 (1972). The more important message conveyed by Jeffers is found not in the bare judgment, but in the plurality's conclusion, joined by the four dissenters, that CCE and conspiracy are insufficiently distinct to justify a finding that Congress intended to allow punishments for both when they rest on the same activity.

V

Finally, the Government argues that Congress must have intended to allow multiple convictions because doing so would provide a "backup" conviction, preventing a defendant who later successfully challenges his greater offense from escaping punishment altogether — even if the basis for the reversal does not affect his conviction under the lesser. Brief for United States 20-22. We find the argument unpersuasive, for there is no reason why this pair of greater and lesser offenses should present any novel problem beyond that posed by any other greater and lesser included offenses, for which the courts have already developed rules to avoid the perceived danger.

In Tinder v. United States, 345 U.S. 565, 570 (1953), the defendant had been convicted of theft from a mailbox and improperly sentenced to prison for more than one year even though the evidence only supported a misdemeanor conviction. Exercising our "power to do justice as the case requires" pursuant to 28 U.S.C. § 2106, we ordered the District Court to correct the sentence without vacating the underlying conviction. Relying on Tinder and the practice in "state courts, including courts governed by statutes virtually the same as Section 2106," the Court of Appeals for the District of Columbia Circuit later decided that its "power to modify erroneous judgments authorizes reduction to a lesser included offense where the evidence is insufficient to support an element of the [greater] offense stated in the verdict." Austin v. United States, 382 F.2d 129, 140, 141-143 (1967).

Consistent with the views expressed by the District of Columbia Circuit, federal appellate courts appear to have uniformly concluded that they may direct the entry of judgment for a lesser included offense when a conviction for a greater offense is reversed on grounds that affect only the greater offense. See 8A J. Moore, Federal Practice ¶ 31.03[5], and n. 54 (2d ed. 1995); United States v. Ward, 37 F.3d 243, 251 (CA6 1994) (after finding insufficient evidence to support CCE count, Court of Appeals vacated CCE conviction and sentence and remanded for entry of conspiracy conviction, which District Court had previously vacated as lesser included offense of CCE), cert. denied, 514 U.S. 1030 (1995); United States v. Silvers, 888 F. Supp. 1289, 1306-1309 (ND Md. 1995) (reinstating conspiracy conviction previously vacated after granting motion for new trial on CCE conviction). This Court has noted the use of such a practice with approval. Morris v. Mathews, 475 U.S. 237, 246-247 (1986) (approving process of reducing erroneous greater offense to lesser included offense as long as the defendant is not able to demonstrate that "but for the improper inclusion of the [erroneous] charge, the result of the proceeding probably would have been different"). See also Jones v. Thomas, 491 U.S. 376, 384-385, n. 3 (1989) (citing Morris).

There is no need for us now to consider the precise limits on the appellate courts' power to substitute a conviction on a lesser offense for an erroneous conviction of a greater offense. We need only note that the concern motivating the Government in asking us to endorse either the Seventh Circuit's practice of entering concurrent sentences on CCE and conspiracy counts, or the Second Circuit's practice of entering concurrent judgments, is no different from the problem that arises whenever a defendant is tried for greater and lesser offenses in the same proceeding. In such instances, neither legislatures nor courts have found it necessary to impose multiple convictions, and we see no reason why Congress, faced with the same problem, would consider it necessary to deviate from the traditional rule.

VI

A guilty verdict on a § 848 charge necessarily includes a finding that the defendant also participated in a conspiracy violative of § 846; conspiracy is therefore a lesser included offense of CCE. Because the Government's arguments have not persuaded us otherwise, we adhere to the presumption that Congress intended to authorize only one punishment. Accordingly, "[o]ne of [petitioner's] convictions, as well as its concurrent sentence, is unauthorized punishment for a separate offense" and must be vacated. Ball, 470 U.S., at 864.

The judgment of the Court of Appeals is reversed, and the case is remanded for further proceedings consistent with this opinion.

It is so ordered.