This сase deals with the interpretation of 18 U.S.C. § 3624(b), which governs the calculation of credits awarded to federal prisoners for good behavior. The petitioner argues that the interpretation of this provision by the Bureau of Prisons (BOP), set forth in 28 C.F.R. § 523.20, contravenes the clear language of the statute. He further argues that the rule of lеnity requires that credits be awarded on the basis of the sentence originally imposed rather than on the amount of time actually served and that, even if Chevron deference applies here, the BOP’s interpretation of the statute is not reasonable. We apply Chevron deference to the BOP’s interpretation of § 3624(b) and hold that it is reasonable.
BACKGROUND
Eliot Sash received a twenty-seven month sentence after pleading guilty to one count of identification document fraud and one count of possessing fifteen or more counterfeit or unauthorized access devices. He filed a" petition for habeas corpus pursuant to 28 U.S.C. § 2241, claiming that he should have received 121 days of credit toward the completion of his sentence for good behavior. The BOP, applying a construction of 18 U.S.C. § 3624(b) set forth in 28 C.F.R. § 523.20, awarded Sash only 105 days of credit.
Sash was released on November 22, 2004, having served 17 days more than he contends the law allows. He must still complete an eight-year term of supervisеd release, which he argues should be reduced because of the excess imprisonment he has suffered.
See
28 U.S.C. § 2243 (district court shall dispose of habeas applications “as law and justice' require”). The United States District Court for the Eastern District of New York (Garaufis, J.) denied Sash’s petition in a thoughtful and thorough opinion.
See Sash v. Zenk,
Section 3624(b) of Title 18 of the United States Code governs credit toward service of sentence for prisoners who behave well, commonly referred to as “good time credit”:
[A] prisoner who is serving a term of imprisonment of more than 1 year[,] other than a term of imprisonment for the duration of the prisoner’s life, may receive credit toward the sеrvice of the prisoner’s sentence, beyond the time served, of up to 54 days at the end of each year of the prisoner’s term of imprisonment, beginning at the end of the first year of the term, subject to determination by the Bureau of Prisons that, during that year, the prisoner has displayed exemplary compliance with institutional disciplinary regulations.... [I]f the Bureau determines that, during that .year,.the prisoner has not satisfactorily complied with such institutional regulations, the prisoner shall receive no such credit toward service of the prisoner’s sentence or shall receive such lesser credit as the Bureau determines to be *134 appropriate.... Credit that has not been earned may not later be granted.... [CJredit for the last year or portion of a year of the term of imprisonment shall be prorated and credited ■within the last six weeks of the sentence.
The BOP interprets this statute to mean that an inmate in Sash’s position receives “54 days credit ... for each year served.” 28 C.F.R. § 523.20 (emphasis added). Sash interprets it to mean that the inmate receives 54 days of credit for each year of the sentence as imposed. Because every well-behaved inmate serves less time than called for by the original sentence, Sash’s interpretation would result in more credit for well-behaved prisoners.
DISCUSSION
We review the district court’s denial of Sash’s petition for habeas corpus
de novo. See Richards v. Ashcroft,
I. Chevron Deference, Not the Rule of Lenity, Governs Our Review of This Case
Sash argues that
Chevron
deference should apply only after we have employed the rule of lenity to resolve statutory ambiguities in favor of the prisoner.
See Chevron, U.S.A., Inc. v. Natural Res. Def. Council,
It is true that the rule of lenity “applies not only to interpretations of the substantive ambit of criminal prohibitions, but also to the penalties they impose.”
Bifulco v. United States,
The rule of lenity has two purposes: first, to ensure that the public receives fair notice of what behavior is criminal and what punishment applies to it,
see Ladner v. United States,
The statutory ambiguity of § 3624(b) does not result in any laсk of notice to potential violators of the law of the scope of the punishment that awaits them, because the award or withholding of credit under § 3624(b) is not part of that punishment. Sentencing credits are awarded to ensure administrative order in prison, not to further the punitive goals of the erimi-
*135
nal law.
Cf. Porter v. Coughlin,
The second concern underlying the rule of lenity is also not relevant here because the regulation is not criminal in nature. No court has infringed upon the role оf the legislature by creating a criminal sanction where none existed before. Nor has the BOP infringed upon the courts’ role in determining the appropriate sentence to be imposed on an offender within the parameters of the statute. The award, of credit for good behavior under § 3624(b) is certainly not intended to diminish the strеngth of the community’s condemnation of the underlying act, as expressed in the statute, nor the individual determination of culpability reflected in the sentence imposed by the court.
Because the purposes of the rule of lenity are not implicated here, we hold that it does not apply to the BOP’s construction of § 3624(b).
Cf. Yi v. Fed. Bureau of Prisons,
For the same reason, we reject Sash’s argument that
Chevron
deference is inappropriate here. The BOP is the agency charged with implementing the statutory provision at issue in this case.
See
18 U.S.C. § 3624.
Chevron
therefore instructs us to defer to the BOP’s interpretаtion if 'the statute is ambiguous.
See Chevron,
Sash argues that
Chevron
deference is inappropriate because the statute at issue is criminal in nature. As we noted in
Michel v. INS,
We note that the Supreme Court has on at least two occasions given deference to BOP interpretations of sentence-administration statutes.
See Lopez v. Davis,
II. § 3624(b) Is Ambiguous, and the BOP’s Interpretation Is Reasonable
We join our sister circuits in holding that § 3624(b) is ambiguous and that
Chevron
deference therefore applies.
See Perez-Olivo,
Sash argues that the BOP’s interpretation is unreasonable because § 3624(b) unambiguously requires that good time be calculated on the basis of the sentеnce imposed. He points out that the phrase “term of imprisonment” appears several times in § 3624 and in most instances refers to the sentence, not the amount of *137 time served. But there is other language in this statute referring back to the phrase “term of imprisonment” which seems to contradict Sash’s reading. A clause in the first sentеnce of § 3624(b) suggests that the phrase “each year of the term of imprisonment” refers to actual years: “[A] prisoner ... may receive credit ... of up to 54 days at the end of each year of the prisoner’s term of imprisonment ... subject to determination by the [BOP] that, during that year, the prisoner has displayed exemplary compliance” (emphasis added).
Sash’s interpretation would require us to read “during that year” to mean “during a hypothetical year of his sentence.” In other words, the BOP would be required to determine whether a prisoner had behaved well during a year which was partly, if not wholly, hypothetical.
3
This appears to conflict with § 3624’s directive that good timе be calculated at the end of each year on the basis of behavior “during that year” — in other words, on the basis of a prisoner’s actual behavior.
See Sash,
Sash relies on language in § 3624 providing for “credit toward the service of the prisoner’s
sentence, beyond the time served.”
§ 3624(b) (emphasis added). He reads this language to mean “credit based on the total sentеnce, irrespective of time actually served.” The BOP’s interpretation, Sash suggests, renders the phrase “sentence, beyond the time served” meaningless. As the district court noted, none of the courts that have decided this issue have been able to explain what “beyond the time served” means.
See Sash,
Sash further points out that the BOP’s interpretation leads to a more complicated calculation than his interpretation would.
4
Admittedly, one purpose of the new statute was to make the “computation of credit toward early release pursuant to section 3624(b) ... considerably less complicated than under current law.” S. Rep. 98-225, at 146 (1983),
reprinted in
1984 U.S.C.C.A.N. 3182, 3329. But § 3624 simplified the calculation in other ways,
see Pacheco-Camacho,
Whether or not legislative history may be appropriately used in the first step of a
Chevron
analysis,
5
the legislative history of
*138
§ 3624(b) offers nothing that could usefully guide us here.
Cf. Perez-Olivo,
Finally, we reject Sash’s argument that this Circuit adopted his reading of § 3624(b) in
United States v. Tocco,
CONCLUSION
For the foregoing reasons, the judgment of the district court is Affirmed.
Notes
. Sash argues that the deference afforded the BOP in
Lopez
is inappropriate here because that case involved an "actual delegation оf discretion,” as opposed to an implied delegation like the one here. Even if this distinction were apt,
see Lopez,
.
Sash argues that
Koray
is inapplicable because in that case the Supreme Court found no ambiguity in the language of the statute governing credit for prior custody. In
Koray,
the Supreme Court first interpreted the statute without reference to the agency interpretation, then noted that the BOP had reached the same interpretation in an internal agency guideline, which was entitled to deference because it adopted a " 'permissible construction of the statute.’ ”
Koray,
[RJespondent’s is not the only plausible interpretation of the language; it would be too much to say that the statute cannot bear the interpretation adopted by the Bureau. And in light of the foregoing textual and historical analysis, the initial plausibility of respondent’s reading simply does not carry the day.
Id. at 62 (internal citations and quotation marks omitted). Even if Sash is correct that the Court's statements on deference to the BOP in Koray were dicta, the Court's explanation is persuasive and supports the conclusion we independently reach: the BOP is the agency chargеd with administering criminal sentences and deserves deference here.
.In a ten-year sentence, for example, more than one year might be taken off for good behavior, in which case the BOP would have to determine the extent of the prisoner's compliance during a wholly nonexistent year. Perhaps it would be reаsonable to assume that a well-behaved prisoner would continue behaving well during this hypothetical time, but nothing in the statute directs the BOP to make such an assumption.
. Sash's interpretation is indeed simpler. For a ten-year sentence, for example, "what could be easier than multiplying fifty-four by ten?”
Perez-Olivo,
.
See Coke v. Long Island Care At Home, Ltd.,
