with whom FAGG, BOWMAN, WOLLMAN, BEAM, and HANSEN, Circuit Judges, join.
The issue in this case is whether a pre-sentence defendant held in a halfway house should receive credit, postconviction, on his sentence under 18 U.S.C. § 3585(b) (1988). Robert Scott Moreland appealed the district court’s1 denial of his petition for a writ of habeas corpus under 28 U.S.C. § 2255. A divided panel of this court reversed and remanded with instructions to credit More-land for time spent at the halfway house. Moreland v. United States, 932 F.2d 690 (8th Cir.), vacated, reh'g en banc granted sub nom. United States v. Moore, 951 F.2d 166 (8th Cir.1991). We granted rehearing en banc. We now fall in line with the First, Second, Fourth, Fifth, Seventh and Tenth Circuits, and reject the reasoning of the Ninth Circuit. We find that Moreland was not in official detention while at the halfway house, and affirm the district court.
I.
The background facts of this case are more fully set out in the panel opinion, Moreland, 932 F.2d 690, and we will not repeat them here except as necessary to address the arguments on appeal.
Moreland was arrested on July 28, 1989, on two counts of bank fraud, in violation of 18 U.S.C. § 1344, and two counts of using false social security cards, in violation of 42 U.S.C. § 408(g)(2). Moreland was released on bond on September 5, 1989. He was ordered to reside at the Reentry Services Community Treatment Center (RSCTC) pending trial. On October 30, 1989, More-land pleaded guilty to one count of fraud. He continued to reside at RSCTC prior to his sentencing.2 After beginning to serve his sentence in federal prison, Moreland filed a petition with the Bureau of Prisons (BOP) requesting that he be given credit against his sentence for the time he spent at RSCTC prior to sentencing. BOP denied his request. Moreland then filed a petition in federal district court asking for habeas relief. The district court denied the petition because it determined that Moreland was not in “official detention” while at RSCTC. Moreland appeals to this court on two grounds. First, Moreland contends that he was in “official detention” under 18 U.S.C. § 3585(b) (1988)3 while he resided at *657RSCTC. Second, Moreland argues that denial of credit for his presentence “detention” violates the equal protection clause because postsentence detainees4 residing at RSCTC receive credit for their time at RSCTC.
II.
A. “Official Detention”
Moreland’s first argument hinges on the definition of “official detention” under § 3585(b). If “official detention” includes presentence residence in a halfway house, Moreland should get credit for the time he spent at RSCTC. If, however, such time does not fall under the definition of “official detention,” the district court was correct and Moreland should not get credit for that time.
The term “official detention” is ambiguous. Congress did not provide a clear definition in either the statute or in its legislative history. See 18 U.S.C. § 3585(b); S.Rep. No. 225, 98th Cong., 2d Sess. 128-29, reprinted in 1984 U.S.C.C.A.N. 3182, 3312. The disagreement among the circuits over the interpretation of this phrase emphasizes its abstruseness. Compare, e.g., United States v. Woods, 888 F.2d 653, 655 (10th Cir.1989) (“ ‘official detention’ means imprisonment in a place of confinement, not stipulations or conditions imposed upon a person not subject to full physical incarceration”), cert. denied, 494 U.S. 1006, 110 S.Ct. 1301, 108 L.Ed.2d 478 (1990), with Brown v. Rison, 895 F.2d 533 (9th Cir.1990) (“official detention” can include pretrial residence in community treatment center where conditions approached those of incarceration). Because the phrase is ambiguous, we must look outside the statute to determine its parameters.5
In Chevron U.S.A., Inc. v. Natural Resources Defense Council, 467 U.S. 837, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984), the Supreme Court held that if a statute is “silent or ambiguous with respect to the specific issue,” and if “the [administering] agency’s answer is based on a permissible construction of the statute,” we must defer to the agency’s interpretation. The BOP, as administering agency, resolved this ambiguity in its Program Statement on Sentence Computation, Jail Time Credit Under 18 U.S.C. § 3568.6
*658Time spent in residence in a residential community center (or a community based program located in a Metropolitan Correctional Center or jail) ... as a condition of bail or bond ... is not creditable as jail time since the degree of restraint provided by residence in a community center is'not sufficient restraint to constitute custody within the meaning or intent of 18 USC 3568.... However, time spent in a jail-type facility (not including a community based program located in a Metropolitan Correctional Center or jail) as a condition of bail or bond is creditable as jail time because of the greater degree of restraint.
BOP Program Statement 5880.24(5)(b)(5) (emphasis in original). We believe this is both a reasonable and a permissible construction of § 3585 for a number of reasons.
First,' the BOP makes a clear distinction between residential community centers and jail-type facilities based on their respective degrees of restraint. It explicitly grants sentencing credit when a presentence defendant is placed under a great degree of restraint. Thus, it is clear that the BOP has considered this issue and has made a reasoned determination.
Second, the great weight of the legal authority that has addressed this issue supports the conclusion that “official detention” does not include presentence residence in a halfway house. In Ramsey v. Brennan, 878 F.2d 995 (7th Cir.1989) (interpreting § 3568), the Seventh Circuit refused to grant sentence credit for time spent in a halfway house. The court opined that whether the deprivation of liberty associated with confinement in a halfway house, a “twilight zone between prison and freedom,” qualifies as “official detention” was not “a question susceptible of rational determination, at least by tools of inquiry available to judges.” Id. at 996. Instead of making such a determination, the court deferred to the BOP Program Statement that prohibits using time spent in a residential community center as credit toward jail time. Id. (quoting BOP Program Statement No. 5880.24(5)(b)(5)).
In United States v. Woods, 888 F.2d 653 (10th Cir.1989) (interpreting § 3585(b)), cert. denied, 494 U.S. 1006, 110 S.Ct. 1301, 108 L.Ed.2d 478 (1990), the Tenth Circuit reached the same result without relying on the BOP Program Statement. The Woods court held that “official detention” means “imprisonment in a place of confinement, not stipulations or conditions imposed upon a person not subject to full physical incarceration.” Id. at 655. Consequently, the court held that presentence detention in a halfway house could not be used for sentence credit. Id.
The Fourth Circuit, following Woods, found that “official detention” requires full physical incarceration. United States v. Insley, 927 F.2d 185, 186 (4th Cir.1991); see also United States v. Zackular, 945 F.2d 423, 424-25 (1st Cir.1991) (“official detention” requires incarceration as a precondition to credit); Mieles v. United States, 895 F.2d 887, 888 (2d Cir.1990) (“jail-time credit under section 3568 requires physical confinement”); United States v. Smith, 869 F.2d 835, 837 (5th Cir.1989) (“custody” under § 3568 is characterized by incarceration) (quoting Polakoff v. United States, 489 F.2d 727, 730 (5th Cir.1974)). Our own circuit has also found that “custody” under § 3568 “relates to actual custodial incarceration.” Villaume v. United States Dep’t of Justice, 804 F.2d 498, 499 (8th Cir.1986), cert. denied, 481 U.S. 1022, 107 S.Ct. 1908, 95 L.Ed.2d 514 (1987).
*659Only one circuit has decided that actual incarceration is not necessary for credit to be granted under § 3568. In Brown v. Rison, 895 F.2d 533 (9th Cir.1990), the Ninth Circuit granted jail-time credit for pretrial residence in a halfway house. It concluded that the BOP interpretation “excludes [from sentencing credit] enforced residence under conditions approaching those of incarceration.” Id. at 536. Although the court recognized that it “must accord substantial deference to an interpretation of section 3568 by the agency charged with its administration, and must accept that interpretation if it is a reasonable one,” id. at 535, it went on to decide that excluding enforced residence under conditions approaching incarceration would be contrary to the considerations of fairness underlying Congress’ provision of credit for time served. Id. at 536. We think Brown was wrongly decided.
The Ninth Circuit’s interpretation of the BOP Program Statement is incorrect. The Statement clearly says that “time spent in a jail-type facility (not including a community based program located in a Metropolitan Correctional Center or jail) as a condition of bail or bond is creditable as jail time because of the greater degree of restraint.” BOP Program Statement 5880.-24(5)(b)(5) (emphasis in original). This provision makes allowance for “conditions approaching those of incarceration” because it takes into account both the type of facility and the amount of restraint imposed. Thus, the BOP interpretation actually answers the Ninth Circuit’s concerns. Second, the fact that the great weight of legal authority has decided that “custody” or “official detention” require physical incarceration indicates that this interpretation is reasonable. Therefore, we believe that the Ninth Circuit incorrectly declined to defer to the BOP interpretation as it was required to do under Chevron.7
Third, other relevant statutes indicate that Moreland was not in detention when he resided at RSCTC, but rather was granted a conditional release. Presentence defendants who are permitted to reside in a halfway house are not in detention under the Release and Detention Pending Judicial Proceedings chapter of the U.S.Code. 18 U.S.C. §§ 3141-3156 (1988). At a criminal defendant’s first appearance before a judicial officer after arrest, the defendant is either detained or released (with or without conditions). 18 U.S.C. § 3142(a). If the defendant is detained, the detention order must include language that directs that the defendant be “committed to the custody of the Attorney General for confinement in a corrections facility_” 18 U.S.C. § 3142(i)(2).8 If the defendant is released, however, the judicial officer must impose the “least restrictive” conditions that “will reasonably assure the appearance of the person as required and the safety of any other person and the community....” 18 U.S.C. § 3142(c)(1)(B). The most restrictive form of release the officer- can impose requires, inter alia, the defendant to “remain in the custody of a designated person, who agrees to assume supervision and to report any violation of a release condition to the court_” 18 U.S.C. § 3142(e)(l)(B)(i). When a presentence defendant is released to a halfway house, he is placed in the custody of the proprietors of the halfway house, not the Attorney *660General, and therefore is not in detention.9 Consistency would require that the defendant also not be considered in “official detention” for purposes of sentencing credit.10
B. Equal Protection
Moreland also argues that BOP’s denial of sentence credit for his presen-tence detention in RSCTC violated the equal protection clause because other prisoners received credit for their time at RSCTC. Presentence defendants are not a suspect class. Therefore, we review More-land’s equal protection argument under a rational basis standard. See Cleburne v. Cleburne Living Center, Inc., 473 U.S. 432, 439-41, 105 S.Ct. 3249, 3254-55, 87 L.Ed.2d 313 (1985). Under this standard of review, Moreland prevails if (1) persons who are similarly situated are treated differently by the government, and (2) the government fails to provide a rational basis for the dissimilar treatment. Id.
Moreland contends that the district court should have adopted the Eleventh Circuit’s approach in Johnson v. Smith, 696 F.2d 1334 (11th Cir.1983). In Johnson, the court stated that treating presentence defendants and postsentence defendants differently would not violate the Constitution if (1) conditions for presentence defendants were less restrictive than for postsentence defendants, or (2) the government had a rational reason for the disparate treatment of the two similarly situated groups. Id. at 1337 (emphasis added). However, the Johnson court was not required to and did not consider the antecedent question of whether presentence defendants and post-sentence defendants are similarly situated because the government had conceded they were in the district court. Id. at 1338. Moreland does not have the benefit of such a concession in this case. We find that the Johnson holding does not apply to this case because presentence defendants and post-sentence defendants are legally distinct from one another and, therefore, are not similarly situated. See Woods, 888 F.2d at 656 (as a matter of law, presentence defendants and postsentence defendants are not similarly situated because of divergent legal status).
Presentence defendants in a halfway house have a different legal custody status than postsentence defendants. A presen-tence defendant is under the custody of the proprietors of the halfway house. He is released there by a judicial officer whose statutory goal is to impose the least restrictive conditions possible upon the defendant’s liberty. In contrast, a postsentence defendant is in the custody of the Attorney General and under the authority of the BOP. Upon receiving custody, BOP initiates a procedure to determine the postsen-tence defendant’s security level (i.e., Minimum, Low, Medium, or High). In making this determination, the BOP considers a myriad of factors which include aspects of the conviction, judicial recommendations, public safety factors, potential to cause institutional disruption and escape potential. Bureau of Prisons, Security Designa*661tion & Custody Classification Manual, Program Statement 5100.3, Ch. 8 (1991). Based upon the security level, postsentence defendants are assigned to high security facilities (penitentiaries); medium security facilities with double fences, gun towers and armed perimeter patrols; low security facilities with a single fence, no gun towers and reduced security; or minimum security with no fences and minimal security (e.g., halfway houses). Therefore, even though a postsentence defendant and a presen-tence defendant may both spend time in a halfway house, the BOP is not obligated to treat them similarly because they were put in the halfway house under significantly different legal conditions.
III.
Because Moreland was not in “official detention” within the meaning of § 3585(b) while at RSCTC and because there was no equal protection violation in treating pre-sentence defendants differently from post-sentence defendants for purposes of giving jail-time credit for time spent in a halfway house, we affirm the district court’s denial of Moreland’s habeas petition.
. The Honorable Donald D. Alsop, Chief Judge, United States District Court for the District of Minnesota.
. Moreland was sentenced on February 2, 1990. He actually resided at RSCTC until March 12, 1990, when he began serving his sentence at a federal prison. Only the time between September 5, 1989, and February 2, 1990, is at issue in this case. Therefore, all allusions in this opinion to the time Moreland spent at RSCTC will refer specifically to the time prior to sentencing.
. Section 3585(b) provides:
(b) Credit for prior custody. — A defendant shall be given credit toward the service of a term of imprisonment for any time he has spent in official detention prior to the date the sentence commences—
(1) as a result of the offense for which the sentence was imposed; ...
*657that has not been credited against another sentence.
18 U.S.C. § 3585(b) (emphasis added).
. At this point, the criminal defendant or detainee is more properly referred to as “prisoner” or "inmate," but to simplify the discussion, we will use the phrase "postsentence defendant” or "postsentence detainee.”
. The concurrence suggests that the word "detention” in § 3585(b) "incorporates the definition contained in § 3142.” See infra. Section 3142 delineates the circumstances under which a federal judge may order that a federal prisoner be detained before trial. We agree that the term "detention" as applied in § 3142 is incorporated in the phrase "official detention” in § 3585(b). See infra p. 659. We believe this result is dictated both by the role of § 3142 and its application in the federal judicial system, and by our previous decisions under § 3568, see infra pp. 657-58 n. 6, requiring actual physical incarceration for a prisoner to receive credit. See United States v. Carlson, 886 F.2d 166, 166 (8th Cir.1989); Villaume v. United States Dep't of Justice, 804 F.2d 498, 499 (8th Cir.1986), cert. denied, 481 U.S. 1022, 107 S.Ct. 1908, 95 L.Ed.2d 514 (1987).
We do not believe, however, that acknowledging the role played by § 3142 ends our inquiry. There are situations, not before us now, that § 3142 does not address. One example is a defendant who spends time in state custody on a charge that evolves into a federal offense. See infra p. 660 n. 10. We believe that the existence of such cases shows that the phrase "official detention” in § 3585(b) is ambiguous.
The concurrence states "the Bureau of Prisons retains the discretion to determine, in the first instance whether time spent in presentence custody not controlled by the federal trial court under § 3142 rises to the level of ‘official detention’ for purposes of § 3585(b).” Infra pp. 657-58 n. 6. Absent some evidence that Congress intended such a result, however, we will not create a dual system of authority to govern grants of credit for presentence detention.
. 18 U.S.C. § 3585 replaced 18 U.S.C. § 3568. Section 3568 uses the term "custody” instead of "official detention.” There is no indication that Congress intended to change the application of the statute for purposes of granting credit on a prisoner’s sentence. See S.Rep. No. 225, 98th Cong., 2d Sess. 128-29, reprinted in 1984 U.S.C.C.A.N. 3182, 3311-12. "Subsection (b) provides that the defendant will receive credit towards the sentence of imprisonment for any time he has spent in official custody_" Id. at 3312 (emphasis added). In Woods, 888 F.2d 653, the court said that "Congress did 'not intend a different result’ from the old statute *658because only time served in ‘official custody' could be credited against jail time.” Id. at 655. We agree with this analysis. See also Pinedo v. United States, 955 F.2d 12, 13 (5th Cir.1992); United States v. Becak, 954 F.2d 386, 387 (6th Cir.1992); United States v. Insley, 927 F.2d 185, 186 (4th Cir.1991).
The concurrence argues that United States v. Wilson, - U.S. -, 112 S.Ct. 1351, 117 L.Ed.2d 593 (Mar. 24, 1992), forecloses our finding that the term "official detention" means the same thing as the term "custody.” We disagree. The statement cited is dicta and does not find that' this change is meaningful. It simply remarks that the statute was changed in several ways. Id. - U.S. at -, 112 S.Ct. at 1355-56. We do not think this precludes our approach here. We find, therefore, that the term "custody" under § 3568 means the same thing as the phrase "official detention” under § 3585.
. Even if Brown were correct, however, it would not apply in this case because the liberty restrictions in Brown were greater than those placed upon Moreland in RSCTC. In Brown, the curfew lasted from 7:00 p.m. to 5:00 a.m. and during that time the prisoners were allowed no outside contact. In contrast, Moreland's curfew lasted from midnight to 8:00 a.m. with limited phone privileges. While Moreland was subject to some of the restrictions present in Brown-no drugs, no alcohol, drug testing, and limited travel — Moreland still had much more liberty in RSCTC than he would have had in jail.
. The fact that a detained defendant is committed to the custody of the Attorney General and a released defendant is not is particularly important. “There exists a strong presumption that ‘custody’ refers to the legal authority of the custodian.... The physical conditions to which federal inmates are subjected vary widely.... The only common link among all those settings is that the inmates are always subject to the authority of the Attorney General." Randall v. Whelan, 938 F.2d 522, 525 (4th Cir.1991).
. It is important to note that, when determining the conditions of release, the judicial officer must maintain the presumption of innocence of the presentencing defendant. 18 U.S.C. § 3142(j). Once a defendant has been found guilty of a crime, the presumption of innocence is replaced by a presumption of detention. This presumption, however, can be overcome. See, 18 U.S.C. § 3143(a). If a presentencing defendant has been found guilty and remains in a halfway house without a transfer of custody to the Attorney General, then it is clear that the presumption of detention has been overcome and the presentencing defendant is still on conditional release.
. We do not believe § 3142 governs the definition of the word “detention” in § 3585(b) because it does not cover all cases where credit should be granted. Consider, for example, a defendant who spent time in state custody on a charge that evolved into a federal offense. This situation seems to us to fall within the term "official detention.” The legislative history of § 3568 specifically provided that a defendant should receive credit for such time. H.R.Rep. No. 1541, 89th Cong., 2d Sess., reprinted in 1966 U.S.C.C.A.N. 2293, 2306; see also Wilson, - U.S. -, 112 S.Ct. 1351 (assuming credit under § 3586(b)). Yet this defendant would not receive credit if § 3142 governed. Absent contrary evidence, we will not assume that Congress intended to create such an inequity between federal defendants — an inequity that results solely from the accident of where a defendant was first incarcerated for an offense.