delivered the opinion of the Court.
We granted certiorari, 414 U. S. 1091 (1973), to resolve a conflict in the Circuits concerning whether, in sentencing a youth offender under other applicable penal statutes, § 5010 (d) of the Federal Youth Corrections Act, 18 U. S. C. § 5005 et seq., requires a federal district court first to make an explicit finding, supported by reasons on the record, that the offender would not benefit from treatment under subsection (b) or (c) of § 5010. The Court of Appeals held that such a finding may be implied from the record, 484 F. 2d 849 (CA7 1973). Three Circuits have taken that position,1 and three Circuits have required an explicit finding accompanied by supporting reasons.2 We conclude that while an express finding of no benefit must be made on the *426record, the Act does not require that it be accompanied by supporting reasons. The judgment of the Court of Appeals is therefore reversed, and the case is remanded to the District Court for further proceedings.
I
On October 19, 1971, a special agent of the Federal Bureau of Narcotics and Dangerous Drugs made arrangements with petitioner’s codefendant, whose case is not before this Court, to purchase approximately 1,000 tablets of lysergic acid diethylamide (LSD) the following day. At the appointed hour on October 20, 1971, the undercover agent was shown approximately 1,000 LSD tablets in the possession of petitioner’s co-defendant, who transferred the tablets to the agent. The exhibition and transfer took place in an automobile being driven by petitioner. After the tablets were transferred to the agent but before money had changed hands, petitioner and his codefendant were arrested. The complaint upon which the arrest warrant for petitioner issued charged him with knowingly and intentionally possessing approximately 1,000 tablets of LSD, in violation of 18 U. S. C. §2 and 21 U. S. C. § 844 (a).3 Subsequent to petitioner’s release on his own recognizance, his counsel informed the District Court that petitioner intended to plead guilty to the charge, and requested the completion of a presentence report prior to the plea, as authorized by Fed. Rule Crim. Proc. 32 (c).
On February 14, 1972, proceedings were had in the District Court upon the filing of an information, ar*427raignment, plea, and sentence. The Government filed a one-count information charging petitioner and his co-defendant with a misdemeanor offense under 18 U. S. C. §2 and 21 U. S. C. §844 (a). The Government informed the court that the maximum sentence petitioner and his codefendant, who were first offenders under § 844 (a), could receive was one year in prison, a fine of $5,000, or both; the court was also advised that since petitioner might have been under the age of 26, see n. 9, infra, he “may also be subject to the Federal Youth Corrections Act.”4 App. 6. Petitioner, who was 19 *428years old at the time of the proceeding and had had no prior criminal record, pleaded guilty, as did his code-fendant. After inquiry as prescribed by Fed. Rule Crim. Proc. 11 to determine whether there was a basis in fact for petitioner’s guilty plea, and whether it was entered voluntarily with understanding of its nature and consequences,5 the District Court accepted the plea.
*429Since petitioner desired to be sentenced at this proceeding, the District Court recessed to consider the pre-sentence report, which petitioner’s counsel had already read. After recess and before sentencing, petitioner was given his right to allocution, and petitioner’s counsel requested the court that petitioner “be placed ... on probation under the Youth Corrections Act.” App. 13. See n. 4, supra. Petitioner then received a split sentence which remitted him to the custody of the Attorney General for one year, to serve 90 days’ confinement “in a jail-type' or treatment” institution, although the judgment mentions only a “jail-type” institution; the execution of the remainder of the sentence was suspended and petitioner was placed on probation for two years upon release from custody. 18 U. S. C. § 3651.6 At no time during the proceeding, including *430sentencing, did the District Court make any reference to the Federal Youth Corrections Act.
On May 1, 1972, after having filed numerous other post-conviction motions for relief, petitioner filed the motion at issue here, seeking relief pursuant to Fed. Rules Crim. Proc. 32 (d) and 35, and 28 U. S. C. § 2255, on two grounds. The first alleged that his guilty plea was not made understanding^; that issue is not before us. See n. 5, supra. The second alleged that the District Court was without jurisdiction to impose the sentence given because the court failed to make a finding that petitioner would not derive benefit from treatment under § 5010 (b) or (c), as assertedly required by § 5010 (d). See n. 4, supra. The District Court held an evidentiary hearing to consider this motion, as well as other motions pending at that time. All were denied without opinion. The District Court stated at the post-*431conviction hearing that the Act did not require an affirmative finding that petitioner would not benefit from treatment thereunder before the court could sentence him under other applicable penalty provisions; the court concluded that in committing petitioner for one year under a split sentence “the [District] Court impliedly [held] the Youth Corrections Act not applicable.” App. 45.
The Court of Appeals affirmed, rejecting the view that trial judges must make an explicit finding that youth offenders would not benefit from treatment under the Act. The Court of Appeals held that such a determination may be implied from the record as a whole and that the imposition of the split sentence upon petitioner after his counsel had raised the possibility of sentencing under that Act satisfied § 5010 (d). 484 F. 2d, at 851.
II
The Federal Youth Corrections Act
The sole issue in this case is the validity of the sentence imposed by the District Court. Petitioner contends that before any adult sentence may be imposed § 5010 (d) requires, first, that the sentencing judge find explicitly that the convicted defendant would receive no benefit from treatment under the Act and, second, that the sentencing judge must explain the reasons for his finding. We begin with the general proposition that once it is determined that a sentence is within the limitations set forth in the statute under which it is imposed, appellate review is at an end.7 Gore v. United States, 357 *432U. S. 386, 393 (1958); Townsend v. Burke, 334 U. S. 736, 741 (1948); Blockburger v. United States, 284 U. S. 299, 305 (1932). Our task, therefore, is to determine whether the sentence imposed here was permitted under § 5010 (d) of the Act.
The Federal Youth Corrections Act has been accurately described as the most comprehensive federal statute concerned with sentencing. United States v. Coefield, 155 U. S. App. D. C. 205, 209, 476 F. 2d 1152, 1156 (1973). The Act is in substantial part an outgrowth of recommendations made by the Judicial Conference of the United States more than 30 years ago.8 The principles and procedures contained in the Conference recommendations were in turn largely based on those developed since 1894 for a system of treatment of young offenders in England, known as the Borstal system. See Criminal Justice Act of 1948, 11 & 12 Geo. 6, c. 58, and Criminal Justice Act of 1961, 9 & 10 Eliz. 2, c. 39. Statistics available at the time of the Conference study revealed the two principal motivating factors behind the enactment of the Act: first, the period of life between 16 and 22 years of age was *433found to be the time when special factors operated to produce habitual criminals. Secónd, then-existing methods of treating criminally inclined youths were found inadequate in avoiding recidivism. H. R. Rep. No. 2979, 81st Cong., 2d Sess., 2-3 (1950) (hereinafter H. R. Rep. No. 2979). The Act was thus designed to provide a better method for treating young offenders convicted in federal courts in that vulnerable age bracket, to rehabilitate them and restore normal behavior patterns. Ibid.
To accomplish this objective, federal district judges were given two new alternatives to add to the array of sentencing options previously available to them, see n. 9, infra: first, they were enabled to commit an eligible offender to the custody of the Attorney General for treatment under the Act. 18 U. S. C. §§ 5010 (b) and (c). Second, if they believed an offender did not need commitment, they were authorized to place him on probation under the Act. 18 U. S. C. § 5010 (a). If the sentencing court chose the first alternative, the youth offender would be committed to the program of treatment created by the Act.
The objective of these options represented a departure from traditional sentencing, and focused primarily on correction and rehabilitation. All persons under 22 years of age at the time of conviction were made eligible for probation or treatment under the Act,9 the latter de*434fined as “corrective and preventive guidance and training designed to protect the public by correcting [their] antisocial tendencies.” 18 U. S. C. §§ 5006 (e) and (g). To implement the program of treatment for youth offenders committed under the Act, a Youth Correction Division was created under the Board of Parole which, in conjunction with the Bureau of Prisons and the Probation Service, operates to provide the unique features of the Act’s program. 18 U. S. C. § 5005.
An important element of the program was that once a person was committed for treatment under the Act, the execution of sentence was. to fit the person, not the crime for which he was convicted. Classification agencies were to be established by the Director of the Bureau of Prisons to receive and study the person committed and make recommendations to the Director as to appropriate treatment. 18 U. S. C. §§ 5014, 5015. Further, the range of treatment available was made broad to provide maximum flexibility. The Director was authorized both to adapt numerous public facilities, and to contract with public or private agencies, in order to provide institutional treatment which the Director could vary according to the committed person’s progress or lack of it. 18 U. S. C. §§ 5011, 5015. An integral part of the treatment program was the segregation of the committed persons, insofar as practicable, so as to place them with those similarly committed, to avoid the influence of association with the more hardened inmates serving traditional criminal sentences. 18 ü. S. C. §5011.
In addition to institutional treatment, the Division was empowered to order conditional release under supervision at any time of those committed under the Act, with fed*435eral probation officers providing the supervision.10 18 U. S. C. §§ 5007, 5017, 5019. Conditional release was mandatory after a period of time fixed by the statutory formula. 18 U. S. C. § 5017. See n. 4, supra. The Division was further authorized to order the unconditional discharge of committed persons after a fixed period of treatment, and was required unconditionally to discharge them within a period also fixed by statutory formula. 18 U. S. C. § 5017. A powerful tool available to the Division was its discretion to discharge committed persons unconditionally before it was required to do so, for upon such discharge the conviction upon which the sentence rested would be automatically set aside. 18 U. S. C. § 5021 (a). See n. 5, supra. Similarly, if the sentencing judge chose the second alternative created by the Act, i. e., placement of the youth offender on probation under its provisions, the judge himself could exercise his discretion to discharge the offender from probation unconditionally. 18 U. S. C. § 5021 (b). See n. 6, supra. This, too, would result in the automatic setting aside of the offender’s conviction. 18 U. S. C. § 5021 (b).
The foregoing describes the new options of treatment and probation made available to the federal sentencing court under the Act.11 Our concern is not with the op*436eration of these alternatives, but with the decision of the court to employ them, for the Act also preserved the power of trial judges to sentence youth offenders under “any other applicable penalty provision.” It is to the question of when a judge may sentence a youth offender outside the Act that we now turn.
Ill
Sentencing Discretion Under the Act (A)
The language affecting the sentencing role of the judge under the Act is found in § 5010 (d), which tells us:
“If the court shall find that the youth offender will not derive benefit from treatment under subsection (b) or (c), then the court may sentence the youth offender under any other applicable penalty provision.”
Our concern is with the effect of the requirement of a “no benefit” finding on the judge’s sentencing discretion.
The legislative history clearly indicates that the Act was meant to enlarge, not restrict, the sentencing options of federal trial courts in order to permit them to sentence youth offenders for rehabilitation of a special sort.
“The proposed legislation is designed to make available for the discretionary use of the Federal judges a system for the sentencing and treatment of [youth offenders] that will promote the rehabilitation of those who in the opinion of the sentencing judge show promise of becoming useful citizens . . . .” H. R. Rep. No. 2979, p. 1. (Emphasis added.)
*437“The purpose of the proposed legislation is to provide a new alternative sentencing and treatment procedure for [youth offenders].” S. Rep. No. 1180, 81st Cong., 1st Sess., 1 (1949) (hereinafter S. Rep. No. 1180). (Emphasis added.)
Thus, apart from the discretion vested in administrative agencies for treatment of those committed under the Act, as described in Part II, the Act was intended to broaden the scope of judicial sentencing discretion to include the alternatives of treatment or probation thereunder.
The Act was a product of studies made by a committee of federal judges under the auspices of the Judicial Conference of the United States. The views of the sponsors as to the effect of the Act on the sentencing discretion of the trial courts are thus of particular importance, and they uniformly support the view that the Act was intended to preserve the unfettered sentencing discretion of federal district judges. Most pertinent is the statement made by the Chairman of the Judicial Conference special committee appointed to study punishment for crime, see n. 8, supra, Chief Judge John J. Parker, who testified before the Subcommittee of the Senate Judiciary Committee, which conducted the only hearings held on the bill (S. 2609) enacted as the Federal Youth Corrections Act. Judge Parker stated:
“[T]he act . . . does not interfere with the power of the judge [with respect to sentencing youth offenders] but gives him merely an alternative method of treatment of those people. . . . He may still give the youthful offender the punishment prescribed by existing statutes, there is nothing in the bill that prevents that. All that the bill does is to provide that if in his judgment and discretion, he thinks that the offender before the court is one that can be treated *438with advantage under this bill, he can sentence him under this bill instead of under the existing law.
. I do not see any possible objection [to the Act]. They say that there are some of these fellows that ought to be given serious punishment notwithstanding their being young and it [the Act] does not prevent their being given serious punishment. Nothing prevents a man from getting 25 years punishment if he deserves it. Nothing prevents his being executed if he deserves such sentence.” Hearings on S. 1114 and S. 2609 before a Subcommittee of the Senate Committee on the Judiciary, 81st Cong., 1st Sess., 43-44 (1949) (hereinafter Hearings).
To the same effect is the statement made by Circuit Judge Orie L. Phillips, the Chairman of the Conference subcommittee which gave particular attention to the treatment of youth offenders. See n. 8, supra. In response to the statement of Senator Kilgore, sponsor of S. 2609, that the bill “takes nothing” (in terms of sentencing) “away from the court,” Judge Phillips replied: “That is correct; it is purely optional.” Hearings 69. Earlier Judge Phillips had said of the bill: “That is merely a flexibility and it is not a command that he send the boys up,” to which Senator Kilgore replied: “I agree with you on that . . . .” Id., at 67. To the extent other testimony and the debates addressed the question of sentencing discretion under the Act, they in-invariably reflected the same view,12 as did the House *439Report, quoted above, and the Department of Justice, which recommended enactment of S. 2609 and noted that the bill “would not deprive the court of any of its present functions as to sentencing.” S. Rep. No. 1180, pp. 10-11. The Senate Report’s language was identical to that of the Department of Justice.13 Id., at 1. The legislative his*440tory of the Act confirms the conclusion that Congress did not intend to alter or circumscribe the sentencing discretion of federal district judges by requiring that any substantive standard be met before the imposition of sentence. There is virtual unanimity of opinion in the legislative history that the Act was intended to increase the sentencing options of federal trial judges, rather than to limit the exercise of their discretion whether to employ the newly created options.
To construe § 5010 (d)’s requirement of a “no benefit” finding to circumscribe that discretion would be incompatible with a clear congressional intent; such a construction would also be at odds with traditional sentencing doctrine. The intent of Congress was in accord with long-established authority in the United States vesting the sentencing function exclusively in the trial court.14
“If there is one rule in the federal criminal prac*441tice which is firmly established, it is that the appellate court has no control over a sentence which is within the limits allowed by a statute.” Gurera v. United States, 40 F. 2d 338, 340-341 (CA8 1930).
See Gore v. United States, 357 U. S. 386 (1958); Townsend v. Burke, 334 U. S. 736 (1948); Blockburger v. United States, 284 U. S. 299 (1932).
The statutes referred to in this line of cases established a permissible range within which sentences could be imposed; if a judge imposed a sentence within that range, his exercise of discretion as to where within the permissible range sentence should be fixed was not subject to challenge. The authority to sentence a youth offender under “any other applicable penalty provision” is expressly reserved to federal trial courts by § 5010 (d), and thus is within the permissible range of sentences which may be imposed under the Act. The “no benefit” finding required by the Act is not to be read as a substantive standard which must be satisfied to support a sentence outside the Act, for such a reading would subject the sentence to appellate review even though the sentence was permitted by the Act's terms, thereby limiting the sentencing court's discretion. We will not assume Congress to have intended such a departure from well-established doctrine without a clear expression to disavow it. As our review has shown, the exclusive sentencing power of district judges was acknowledged, and Congress' intention to affirm that power was clearly indicated.
From our conclusion that a finding of “no- benefit” was not intended to constitute a substantive standard, it follows that a sentence outside the Act need not be accompanied by a statement of reasons why the court chose such a sentence. The only purpose of such a requirement would be to facilitate appellate supervision of, and thus to *442limit, the trial court’s sentencing discretion.15 In short, we hold that the discretion vested in a district judge under § 5010 (d) is essentially the same as the traditional discretion vested in the court, for example, to impose the minimum sentence on a first offender or a larger sentence on a recidivist. If the failure of a court to sentence a particular youth offender under the Act appears “too harsh, the remedy must be afforded by act of Congress, not by judicial legislation under the guise of construction,” Block-burger, supra, at 305, since “[wjhatever views may be entertained regarding severity of punishment . . . [t]hese are peculiarly questions of legislative policy.” Gore, supra, at 393.
(B)
Although the Act was not in any way intended to circumscribe the discretion of sentencing courts, it did provide a new sentencing alternative designed to prevent youthful offenders from continuing their involvement in criminal conduct after the expiration of their sentence. In the novelty of the treatment option made available, and the importance of the objective it was to serve, lies the purpose of § 5010 (d)’s requirement that the court find “no benefit” before imposing a sentence other than one under § 5010 (b) or (c).
*443Although well-established doctrine bars review of the exercise of sentencing discretion, limited review is available when sentencing discretion is not exercised at all. Yates v. United States, 356 U. S. 363, 366-367 (1958) ; United States v. Daniels, 446 F. 2d 967, 972 (CA6 1971); United States v. Williams, 407 F. 2d 940, 945 (CA4 1969). See also n. 7, supra. The requirement of the “no benefit” finding was designed to insure that the sentencing judge exercised his discretion in choosing not to commit a youth offender to treatment under the Act. Such a finding would make unmistakably clear that the sentencing judge was not only aware of the existence of the new Act, but also knew that the youth offender before him was eligible because of his age for the treatment it provided to accomplish its important purpose.
“Appellate modification of a statutorily-authorized sentence ... is an entirely different matter than the careful scrutiny of the judicial process by which the particular punishment was determined. Rather than an unjustified incursion into the province of the sentencing judge, this latter responsibility is, on the contrary, a necessary incident of what has always been appropriate appellate review of criminal cases.” United States v. Hartford, 489 F. 2d 652, 654 (CA5 1974). (Emphasis in original.)
Once it is made clear that the sentencing judge has considered the option of treatment under the Act and rejected it, however, no appellate review is warranted.
The question whether the finding of “no benefit” must be explicit or whether it may be implicit in the record of a particular case is answered by the manifest desire of Congress to assure that treatment under the Act be considered by the court as one option whenever the youth offender is eligible for it. If the finding may be implied *444from the record, appellate courts must go on to determine what constitutes a sufficient showing of the requisite implication. To hold that a “no benefit” finding is implicit each time a sentence under the Act is not chosen would render § 5010 (d) nugatory; to hold that something more is necessary to support the inference that must be found in the record would create an ad hoc rule. Appellate courts should not be subject to the burden of case-by-case examination of the record to make sure that the sentencing judge considered the treatment option made available by the Act. Literal compliance with the Act can be satisfied by any expression that makes clear the sentencing judge considered the alternative of sentencing under the Act and decided that the youth offender would not derive benefit from treatment under the Act.
This case provides an example of the problems arising when the required finding is left to implication. Counsel’s references to the Act followed by the District Court’s sentence indeed afford support for the argument that, by implication, the options of the Act were considered and rejected. However at the post-conviction hearing the District Court found from the record of the sentencing hearing the implication that the Act was “not applicable.” It is thus unclear whether this meant the court believed petitioner to be legally ineligible for treatment under the Act — which would be error — or whether, realizing he was eligible, nevertheless deliberately opted to sentence him as an adult. An explicit finding that petitioner would not have benefited from treatment under the Act would have removed all doubt concerning whether the enlarged discretion Congress provided to sentencing courts was indeed exercised.
Accordingly, the judgment of the Court of Appeals is reversed, and the case is remanded to the end that the *445District Court conduct further proceedings consistent with this opinion.
It is so ordered.
Williams v. United States, 476 F. 2d 970 (CA3 1973); Cox v. United States, 473 F. 2d 334 (CA4 1973) (en banc); United States v. Jarratt, 471 F. 2d 226 (CA9 1972), cert. denied, 411 U. S. 969 (1973); cf. United States v. Walker, 469 F. 2d 1377 (CA1 1972).
Brooks v. United States, 497 F. 2d 1059 (CA6 1974); United States v. Kaylor, 491 F. 2d 1133 (CA2 1974) (en banc); United States v. Coefield, 155 U. S. App. D. C. 205, 476 F. 2d 1152 (1973) (en banc); cf. United States v. Schenker, 486 F. 2d 318 (CA5 1973); see also Small v. United States, 304 A. 2d 641 (DC Ct. App. 1973).
Title 18 U. S. C. § 2 made petitioner punishable as a principal for any offense against the United States committed by his codefendant. Title 21 U. S. C. § 844 (a) makes punishable the knowing or intentional possession of a controlled substance such as LSD when not obtained pursuant to a valid prescription or order, or as otherwise authorized by law.
The sentencing provisions of the Act, 18 U. S. C. § 5010, are as follows:
“(a) If the court is of the opinion that the youth offender does not need commitment, it may suspend the imposition or execution of sentence and place the youth offender on probation.
“(b) If the court shall find that a convicted person is a youth offender, and the offense is punishable by imprisonment under applicable provisions of law other than this subsection, the court may, in lieu of the penalty of imprisonment otherwise provided by law, sentence the youth offender to the custody of the Attorney General for treatment and supervision pursuant to this chapter until discharged by the Division as provided in section 5017 (c) of this chapter; or
“(c) If the court shall find that the youth offender may not be able to derive maximum benefit from treatment by the Division prior to the expiration of six years from the date of conviction it may, in lieu of the penalty of imprisonment otherwise provided by law, sentence the youth offender to the custody of the Attorney General for treatment and supervision pursuant to this chapter for any further period that may be authorized by law for the offense or offenses of which he stands convicted or until discharged by the Division as provided in section 5017 (d) of this chapter.
“ (d) If the court shall find that the youth offender will not derive benefit from treatment under subsection (b) or (c), then the court may sentence the youth offender under any other applicable penalty provision.
“(e) If the Court desires additional information as to whether a youth offender will derive benefit from treatment under subsection *428(b) or (c) it may order that he be committed to the custody of the Attorney General for observation and study at an appropriate classification center or agency. Within sixty days from the date of the order, or such additional period as the court may grant, the Division shall report to the court its findings.”
The release of youth offenders committed under § 5010 is governed by 18 U. S. C. § 5017, which provides in part:
“(a)' The Division may at any time after reasonable notice to the Direétor release conditionally under supervision a committed youth offender. When, in the judgment of the Director, a committed youth offender should be released conditionally under supervision he shall so report and recommend to the Division.
“(b) The Division may discharge a committed youth offender unconditionally at the expiration of one year from the date of conditional release.
“(c) A youth offender committed under section 5010 (b) of this chapter shall be released conditionally under supervision on or before the expiration of four years from the date of his conviction and shall be discharged unconditionally on or before six years from the date of his conviction.
“(d) A youth offender committed under section 5010 (c) of this chapter shall be released conditionally under supervision not later than two years before the expiration of the term imposed by the court. He may be discharged unconditionally at the expiration of not less than one year from the date of his conditional release. He shall be discharged unconditionally on or before the expiration of the maximum sentence imposed, computed uninterruptedly from the date of conviction.”
Although petitioner’s complaint here is that he was not sentenced under the Act, following his conviction he challenged the validity of his plea in part on the ground that he was not informed that under *429the Act he could have received a sentence of incarceration and supervision up to a period of six years, 18 U. S. C. §§ 5010 (b) and 5017 (c), see n. 4, swpra, in asserted violation of Rule 11. The District Court denied relief on this ground; that ruling has not been challenged.
There is no contention made that the District Court could not place petitioner on probation under 18 U. S. C. § 3651, as opposed to probation under the Act, 18 U. S. C. § 5010 (a). See United States v. Kurzyna, 485 F. 2d 517 (CA2 1973). Petitioner was released from confinement to probation on May 11, 1972, with the special condition that his probation terminate May 11, 1974. Although by now petitioner may have fully served his sentence, including probation, he still suffers the disabilities accompanying a criminal misdemeanor conviction under 21 U. S. C. § 844 (a). While the provision under which he was sentenced to probation, 18 U. S. C. § 3651, does not provide for relief from these disabilities, the Act does so in 18 U. S. C. § 5021, by its provision for setting aside the conviction of a youth offender:
“(a) Upon the unconditional discharge by the division of a committed youth offender before the expiration of the maximum sentence imposed upon him, the conviction shall be automatically set aside and *430the division shall issue to the youth offender a certificate to that effect.
“(b) Where a youth offender has been placed on probation by the court, the court may thereafter, in its discretion, unconditionally discharge such youth offender from probation prior to the expiration of the maximum period of probation theretofore fixed by the court, which discharge shall automatically set aside the conviction, and the court shall issue to the youth offender a certificate to that effect.”
Despite the expiration of petitioner’s sentence, then, he may still receive the benefit of 18 U. S. C. § 5021 if he is resentenced under the Act. To be eligible to have his conviction set aside under the Act, petitioner would have to be committed under § 5010 (b) or (c), or placed on probation under § 5010 (a), and achieve the early discharge required by § 5021 (a) or (b). While this might require the imposition of a longer sentence than he originally received, petitioner represents through counsel that he would voluntarily seek re-sentencing which would place him back on probation. Tr. of Oral Arg. 8, 16-18. The District Court would then be able, as a matter of discretion, to provide the requisite early unconditional discharge. 18 U. S. C. §5021 (b).
There is no contention here that the District Court relied upon improper or inaccurate information. United States v. Tucker, 404 U. S. 443 (1972). Petitioner contends he was denied due process because he was deprived of his claimed right to be sentenced under the Act, without a reasoned explanation on the record for the asserted deprivation. We need not address this contention, for it was not raised before the District Court, the Court of Appeals, or in the *432questions presented in the petition for certiorari. Phillips Co. v. Dumas School Dist., 361 U. S. 376, 386 n. 12 (1960); Irvine v. California, 347 U. S. 128, 129-130 (1964); Radio Officers’ Union v. NLRB, 347 U. S. 17, 37 n. 35 (1954).
In 1941 Mr. Chief Justice Stone requested the Judicial Conference to study the general subject of punishment for crime. The Chief Justice appointed four federal courts of appeals judges and three district judges to the committee which undertook the study. A subcommittee gave particular attention to the treatment of youth offenders. The committee made a report to the Judicial Conference in 1942, and developed a draft of an act to provide a correctional system for adult and youth offenders. The report as adopted by the Conference was first presented to Congress in 1943. The recommendations regarding youth offenders were largely adopted by Congress in 1949 in the bill which became the Federal Youth Corrections Act in 1950.
The Act is ordinarily not applied to convicted persons under the age of 18, who are eligible for sentencing under the provisions of the Federal Juvenile Delinquency Act, 18 U. S. C. § 5031 et seq. And certain multiple offenders in the District of Columbia are, despite their qualifying age, barred from sentencing under the Act. D. C. Code Ann. § 22-3202 (d) (1). By contrast, convicted persons between the ages of 22 and 26, termed “young adult” offenders, may be sentenced for treatment under the Act if “the court finds that there is reasonable groun[d) to believe that the defendant will benefit from” treatment under the Act. 18 U. S. C. § 4209. Of *434course, adult offenders are eligible for sentencing only under statutory provisions different from those available for juveniles, youth offenders, and young adult offenders.
In 1952, Congress amended § 5024 of the Act, and added §§ 5025 and 5026, in order to extend the Act’s coverage to youth offenders convicted in the District of Columbia. 66 Stat. 45. In 1967, Congress further amended these sections, withdrawing from the Bureau of Prisons and the Youth Correction Division control of District of Columbia youth offenders during their commitment and after their release. Control during these periods was instead given to the Commissioner of the District of Columbia, who could in turn delegate this authority to the D. C. Department of Corrections, in order to provide continuity of treatment.
11 In recognition of the difficulty of ascertaining whether, and if so which type of, treatment under the Act would benefit a youth offender, the Act also permits the sentencing court to commit the *436offender to one of the above classification agencies where, following observation and study, the Youth Correction Division reports its findings to the court within 60 days. 18 U. S. C. § 5010 (e).
The only other judges to testify before the Senate Subcommittee were also in accord. District Judge Carroll Hincks, who served on the Conference subcommittee studying treatment of youth offenders, stated:
“I think when the judges say they are opposed to the predecessor of this bill, if you could talk with them, you would find that . . . they *439would not themselves want to use it. Very well, they do not have to use it.” Hearings 57.
District Judge Bolitha J. Laws, who served on the Conference special committee studying general punishment for crime,, stated:
“I have already told you that this law is purely an optional situation. A judge who feels that the present system is in all respects perfect and who does not want to use the new provisions, except perhaps rarely, does not have to use them. He still may do one of two things. He may admit the man to probation, or he may send him to an institution exactly as he does now.” Id., at 15.
Mr. James Y. Bennett, Director, Bureau of Prisons, testified similarly:
“I would like to . . . reemphasize more than Judge Laws has done, that this bill is discretionary .... [I]t is very difficult for me to conceive of anybody who could rightfully object to the bill because they can use it or not, as they see fit . . . .” Id., at 25.
During the Senate debate over the bill, Senator Kilgore made clear his position of the matter of sentencing discretion under the bill:
“Its purpose is to grant to trial courts . . . some additional facilities ... to try certain correctional methods. Use of the system provided by this measure would not be mandatory.” 96 Cong. Rec. 8267 (1950).
There was no discussion of sentencing discretion by anyone other than Senator Kilgore in either the Senate or House debates.
The Senate Report also noted that the sentencing judge may sentence a youth offender under applicable provisions other than the Act if, after receiving a pre-sentence diagnosis under 18 U. S. C. § 5010 (e), see n. 11, supra, he is convinced the youth is “incorrigible and would derive no help from the program.” S. Rep. No. 1180, p. 5. The remark was made in the context of a discussion concerning the need sentencing judges have for additional information about youth offenders they must sentence, and indicated merely that temporary commitment under § 5010 (e) would not deprive the judge *440of the discretion to sentence the youth outside the Act, citing illustratively the prototype of youth offender whom judges would not likely desire to sentence under the Act.
To the extent reference was made to the English Borstal system for treating young offenders in drafting the Act, that reference did not include the English view of the trial court’s discretion to make use of that system. Circuit Judge (now Chief Judge) Kaufman of the Court of Appeals for the Second Circuit has stated:
“At present the United States is the only nation in the free world where one judge can determine conclusively, decisively and finally the minimum period of time a defendant must remain in prison, without being subject to any review of his determination.” Symposium, Appellate Review of Sentences, 32 F. R. D. 257, 260-261 (1962).
Professor Sanford H. Kadish also notes that in the United States, the “discretion of the judge ... in [sentencing] matters is virtually free of substantive control or guidance,” Kadish, Legal Norm and Discretion in the Police and Sentencing Processes, 75 Harv. L. Rev. 904, 916 (1962). We are unwilling to ascribe to the Congress an intent to import, sub silentio, sentencing doctrine contrary to traditional powers of sentencing judges.
Judge Marvin E. Frankel (SDNY) has recently stated that while judges are required to explain other rulings, see, e. g., Fed. Rule Civ. Proc. 52 (a), “[t]here is no such requirement in the announcement of a prison sentence.” Frankel, Lawlessness in Sentencing, 41 U. Cin. L. Rev. 1, 9 (1972). It would have been a very simple matter for Congress to have included a statement in § 5010 (d) that the sentencing court’s determination of no benefit must be supported by reasons, as was required by the proposal regarding adult offenders, before the Congress in 1943, S. 895, Tit. II, § 1, 78th Cong., 1st Sess. See n. 8, supra. Congress’ failure to so provide in § 5010 (d) strengthens our view that it intended no new appellate encumbrance upon the sentencing process.
“If the court desires additional information as to whether a youth offender will derive benefit from treatment under subsection *450(b) or (c) it may order that he be committed to the custody of the Attorney General for observation and study at an appropriate classification center or agency. Within sixty days from the date of the order, or such additional period as the court may grant, the Division shall report to the court its findings.” 18 U. S. C. § 5010 (e) (emphasis added).