Three prisoners have alleged that a postsentencing change in the policies of the United States Parole Commission has prolonged their actual imprisonment beyond the period intended by the sentencing judge. The question presented is whether this type of allegation will support a collateral attack on the original sentence under 28 U.S.C. § 2255.1 We hold that it will not.

* With respect to the legal issue presented, the claims before us are identical. To bring this issue into sharp focus, we accept for purposes of decision Addonizio's view of the facts and the relevant aspects of the Parole Commission's practices.

After his conviction in the United States District Court for the District of New Jersey, on September 22, 1970, Addonizio was sentenced to 10 years' imprisonment and a fine of $25,000. Factors which led the District Judge to impose that sentence included the serious character of Addonizio's offenses,2 and the judge's expectation that exemplary institutional behavior would lead to Addonizio's release when he became eligible for parole after serving one-third of his sentence.3 The judge did not contemplate that the Parole Commission might rely on the seriousness of the offense as a reason for refusing a parole which Addonizio would otherwise receive.

In 1973, the Parole Commission markedly changed its policies.4 Under its new practices the gravity of the offense became a significant factor in determining whether a prisoner should be granted parole. Addonizio became eligible for parole on July 3, 1975. After hearings, the Parole Commission twice refused to release him, expressly basing its refusal on the serious character of his crimes.5

Thereafter, Addonizio invoked the District Court's jurisdiction under 28 U.S.C. § 2255 and moved for resentencing. Following the Third Circuit's decision in United States v. Salerno, 538 F.2d 1005, 1007 (1976), the District Court accepted jurisdiction, found that the Parole Commission had not given Addonizio the kind of "meaningful parole hearing" that the judge had anticipated when sentence was imposed, and reduced his sentence to the time already served. The judge stated that he had "anticipated—assuming an appropriate institutional adjustment and good behavior while confined—that [Addonizio] would be actually confined for a period of approximately three and one-half to four years of the ten-year sentence." This "sentencing expectation" was frustrated by the Parole Commission's subsequent adoption of new standards and procedures.

The Court of Appeals affirmed. 573 F.2d 147. Because of a conflict with the decision of the Ninth Circuit holding that § 2255 does not give district courts this type of resentencing authority,6 we granted the Government's petition for certiorari in Addonizio's case and in the consolidated case of two other prisoners in which similar relief was granted.7 439 U.S. 1045, 99 S.Ct. 719, 58 L.Ed.2d 704.

We decide only the jurisdictional issue. We do not consider the Government's alternative argument that the significance of the changes in the Parole Commission's procedures has been exaggerated because it always attached some weight to the character of the offense in processing parole applications. Nor do we have any occasion to consider whether the new guidelines are consistent with the Parole Commission and Reorganization Act of 1976, 90 Stat. 219;8 or whether their enforcement may violate the Ex Post Facto Clause of the Constitution.9

When Congress enacted § 2255 in 1948, it simplified the procedure for making a collateral attack on a final judgment entered in a federal criminal case, but it did not purport to modify the basic distinction between direct review and collateral review. It has, of course, long been settled law that an error that may justify reversal on direct appeal will not necessarily support a collateral attack on a final judgment.10 The reasons for narrowly limiting the grounds for collateral attack on final judgments are well known and basic to our adversary system of justice.11 The question in this case is whether an error has occurred that is sufficiently fundamental to come within those narrow limits.

Under § 2255, the sentencing court is authorized to discharge or resentence a defendant if it concludes that it "was without jurisdiction to impose such sentence, or that the sentence was in excess of the maximum authorized by law, or is otherwise subject to collateral attack." This statute was intended to alleviate the burden of habeas corpus petitions filed by federal prisoners in the district of confinement, by providing an equally broad remedy in the more convenient jurisdiction of the sentencing court. United States v. Hayman, 342 U.S. 205, 216-217, 72 S.Ct. 263, 271, 96 L.Ed. 232.

While the remedy is in this sense comprehensive, it does not encompass all claimed errors in conviction and sentencing. Habeas corpus has long been available to attack convictions and sentences entered by a court without jurisdiction. See, e. g., Ex parte Watkins, 3 Pet. 193, 202-203, 7 L.Ed. 650 (Marshall, C. J.). In later years, the availability of the writ was expanded to encompass claims of constitutional error as well. See Waley v. Johnston, 316 U.S. 101, 104-105, 62 S.Ct. 964, 965-966, 86 L.Ed. 1302; Brown v. Allen, 344 U.S. 443, 73 S.Ct. 397, 97 L.Ed. 469. But unless the claim alleges a lack of jurisdiction or constitutional error, the scope of collateral attack has remained far more limited. Stone v. Powell, 428 U.S. 465, 477 n. 10, 96 S.Ct. 3037, 3044 n. 10, 49 L.Ed.2d 1067. The Court has held that an error of law does not provide a basis for collateral attack unless the claimed error constituted "a fundamental defect which inherently results in a complete miscarriage of justice." Hill v. United States, 368 U.S. 424, 428, 82 S.Ct. 468, 471, 7 L.Ed.2d 417.

Similar limitations apply with respect to claimed errors of fact. The justification for raising such errors in a § 2255 proceeding, as amicus here points out,12 is that traditionally they could have been raised by a petition for a writ of coram nobis, and thus fall within § 2255's provision for vacating sentences that are "otherwise subject to collateral attack." Butcoram nobis jurisdiction has never encompassed all errors of fact; instead, it was of a limited scope, existing "in those cases where the errors were of the most fundamental character, that is, such as rendered the proceeding itself irregular and invalid." United States v. Mayer, 235 U.S. 55, 69, 35 S.Ct. 16, 19-20, 59 L.Ed. 129. Thus, the writ of coram nobis was "available to bring before the court that pronounced the judgment errors in matters of fact which had not been put in issue or passed upon and were material to the validity and regularity of the legal proceeding itself; as where the defendant, being under age, appeared by attorney, or the plaintiff or defendant was a married woman at the time of commencing the suit, or died before verdict or interlocutory judgment." Id., at 68, 35 S.Ct., at 19.

The claimed error here—that the judge was incorrect in his assumptions about the future course of parole proceedings—does not meet any of the established standards of collateral attack. There is no claim of a constitutional violation; the sentence imposed was within the statutory limits; and the proceeding was not infected with any error of fact or law of the "fundamental" character that renders the entire proceeding irregular and invalid.

The absence of any error of this nature or magnitude distinguishes Addonizio's claim from those in prior cases, upon which he relies, in which collateral attacks were permitted. Davis v. United States, 417 U.S. 333, 94 S.Ct. 2298, 41 L.Ed.2d 109, for example, like this case, involved a claim that a judgment that was lawful when it was entered should be set aside because of a later development. The subsequent development in that case, however, was a change in the substantive law that established that the conduct for which petitioner had been convicted and sentenced was lawful. To have refused to vacate his sentence would surely have been a "complete miscarriage of justice," since the conviction and sentence were no longer lawful. The change in Parole Commission policies involved in this case is not of the same character: this change affected the way in which the court's judgment and sentence would be performed but it did not affect the lawfulness of the judgment itself—then or now. Nor is United States v. Tucker, 404 U.S. 443, 92 S.Ct. 589, 30 L.Ed.2d 592, analogous to the present case. In that case, the Court ordered resentencing of a defendant whose original sentence had been imposed at least in part upon the basis of convictions secured without the assistance of counsel. But the error underlying the sentence in Tucker, as the Court emphasized, was "misinformation of constitutional magnitude." Id., at 447, 92 S.Ct., at 591. We have held that the constitutional right to the assistance of counsel is itself violated when uncounseled convictions serve as the basis for enhanced punishment. Burgett v. Texas, 389 U.S. 109, 115, 88 S.Ct. 258, 262, 19 L.Ed.2d 319. Whether or not the Parole Commission action in this case was constitutional, a question not presented here, there is no claim that the action taken by the sentencing judge was unconstitutional, or was based on "misinformation of constitutional magnitude."

Our prior decisions, then, provide no support for Addonizio's claim that he is entitled to relief under § 2255. According to all of the objective criteria—federal jurisdiction, the Constitution, and federal law—the sentence was and is a lawful one. And in our judgment, there is no basis for enlarging the grounds for collateral attack to include claims based not on any objectively ascertainable error but on the frustration of the subjective intent of the sentencing judge.

As a practical matter, the subjective intent of the sentencing judge would provide a questionable basis for testing the validity of his judgment. The record made when Judge Barlow pronounced sentence against Addonizio, for example, is entirely consistent with the view that the judge then thought that this was an exceptional case in which the severity of Addonizio's offense should and would be considered carefully by the Parole Commission when Addonizio became eligible for parole. If the record is ambiguous, and if a § 2255 motion is not filed until years later, it will often be difficult to reconstruct with any certainty the subjective intent of the judge at the time of sentencing. Regular attempts to do so may well increase the risk of inconsistent treatment of defendants; on the other hand, the implementation of the Parole Commission's policies may reduce that risk.

Nothing in the statutory scheme directs sentencing courts to engage in this task on collateral attack; quite to the contrary, the proposed system of sentencing review would be inconsistent with that established by Congress. The decision as to when a lawfully sentenced defendant shall actually be released has been committed by Congress, with certain limitations, to the discretion of the Parole Commission.13 Whether wisely or not, Congress has decided that the Commission is in the best position to determine when release is appropriate, and in doing so, to moderate the disparities in the sentencing practices of individual judges.14 The authority of sentencing judges to select precise release dates is, by contrast, narrowly limited: the judge may select an early parole eligibility date, but that guarantees only that the defendant will be considered at that time by the Parole Commission.15 And once a sentence has been imposed, the trial judge's authority to modify it is also circumscribed. Federal Rule Crim.Proc. 35 now authorizes district courts to reduce a sentence within 120 days after it is imposed or after it has been affirmed on appeal.16 The time period, however, is jurisdictional and may not be extended.17 The import of this statutory scheme is clear: the judge has no enforceable expectations with respect to the actual release of a sentenced defendant short of his statutory term. The judge may well have expectations as to when release is likely. But the actual decision is not his to make, either at the time of sentencing or later if his expectations are not met. To require the Parole Commission to act in accordance with judicial expectations, and to use collateral attack as a mechanism for ensuring that these expectations are carried out, would substantially undermine the congressional decision to entrust release determinations to the Commission and not the courts. Nothing in § 2255 supports—let alone mandates—such a frustration of congressional intent.

Accordingly, without reaching any question as to the validity of the Parole Commission's actions, either in promulgating its new guidelines or in denying Addonizio's applications for parole, we hold that subsequent actions taken by the Parole Commission—whether or not such actions accord with a trial judge's expectations at the time of sentencing—do not retroactively affect the validity of the final judgment itself. The facts alleged by the prisoners in these cases do not provide a basis for a collateral attack on their respective sentences pursuant to § 2255.

The judgments of the Court of Appeals are therefore reversed.

It is so ordered.

Mr. Justice BRENNAN took no part in the decision of this case.

Mr. Justice POWELL took no part in the consideration or decision of this case.