                 FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

SABIL M. MUJAHID,                         No. 03-36038
             Petitioner-Appellant,           D.C. No.
               v.                       CV-02-01719-GMK/
CHARLES A. DANIELS, Warden,                     JMS
            Respondent-Appellee.
                                            OPINION

       Appeal from the United States District Court
                for the District of Oregon
         Garr M. King, District Judge, Presiding

                  Argued and Submitted
        April 11, 2005—San Francisco, California

                   Filed June 27, 2005

     Before: Robert R. Beezer, Sidney R. Thomas, and
           William A. Fletcher, Circuit Judges.

                 Opinion by Judge Beezer




                           7657
                     MUJAHID v. DANIELS                  7659


                         COUNSEL

Stephen R. Sady, Assistant Federal Public Defender, Portland,
Oregon, for the petitioner-appellant.

Kenneth C. Bauman and Craig J. Casey, Assistant United
States Attorneys, Portland, Oregon, for the respondent-
appellee.


                         OPINION

BEEZER, Circuit Judge

   Sabil Mujahid appeals the denial of his 28 U.S.C. § 2241
petition for a writ of habeas corpus, challenging the Bureau
of Prisons’ (“BOP” or “Bureau”) interpretation of the maxi-
mum good time credit a federal prisoner can receive under 18
U.S.C. § 3624(b). Mujahid asserts that the Bureau’s interpre-
tation, which allows a prisoner serving a ten-year sentence to
earn a maximum of 470 days credit, contradicts the statute’s
stated allowance of 54 days of credit per year. We affirm.
7660                    MUJAHID v. DANIELS
                                  I

   The facts relevant to this appeal are not in dispute. In 1995,
the United States District Court for the District of Alaska sen-
tenced Mujahid to ten years imprisonment, plus three years
supervised release, upon his conviction under 18 U.S.C.
§ 922(g)(1) (felon in possession of a firearm). He began his
term in custody on March 21 of that year.

   In 2002, while incarcerated at the Federal Correctional
Institution in Sheridan, Oregon (“FCI-Sheridan”), Mujahid
filed this challenge to the Bureau’s interpretation of the good
time statute. Mujahid’s petition, which he filed in the District
of Oregon, named as respondent the warden at FCI-Sheridan.
The magistrate judge reviewing the petition disagreed with
the assertion that the Bureau’s interpretation deprived
Mujahid of good time credit. The district court adopted the
magistrate judge’s Findings and Recommendations (with one
modification not relevant here) and denied Mujahid’s petition
on November 4, 2003. Mujahid timely appealed.

  The government represents that Mujahid began his three-
year term of supervised release on January 6, 2004.1

                                  II

   As an initial matter, we determine whether events subse-
quent to the district court’s denial of Mujahid’s petition
deprive this court of jurisdiction or render this appeal moot.
The government contends that Mujahid’s placement onto
supervised release prevents us from providing any relief. We
disagree.
  1
    At oral argument, Mujahid’s counsel stated that he believed Mujahid
has since been returned to prison for violating his terms of supervised
release. Our analysis is not contingent on this fact.
                           MUJAHID v. DANIELS                          7661
                                     A

   The government’s first contention, marginally raised in its
briefing and argued at length during oral argument, is that we
lack jurisdiction over this appeal because Mujahid is no lon-
ger imprisoned by the named respondent-warden.2 Established
principles of habeas procedure suggest otherwise.

   [1] When Mujahid filed his petition, he was incarcerated in
Oregon. He filed his petition in district court, in the District
of Oregon. He named as respondent the warden of the institu-
tion where he was imprisoned. These steps properly complied
with habeas procedure. See Rumsfeld v. Padilla, 124 S. Ct.
2711, 2720 (2004). Mujahid’s subsequent transfer and place-
ment onto supervised release do not alter this analysis. As the
government recognizes, a habeas petitioner remains in the
custody of the United States while on supervised release.
Matus-Leva v. United States, 287 F.3d 758, 761 (9th Cir.
2002). And as we stated in Francis v. Rison, 894 F.2d 353,
354 (9th Cir. 1990) (internal quotation marks and citations
omitted), “jurisdiction attaches on the initial filing for habeas
corpus relief, and it is not destroyed by a transfer of the peti-
tioner and the accompanying custodial change.”

                                     B

  The next government challenge asserts mootness. “The bur-
den of demonstrating mootness is a heavy one.” Cantrell v.
  2
    We are unconvinced by the government’s assertion that this argument
cannot be waived. See, e.g., Rumsfeld v. Padilla, 124 S. Ct. 2711, 2717 n.7
(2004) (referring to jurisdiction “in the sense that it is used in the habeas
statute, 28 U.S.C. § 2241(a), and not in the sense of subject-matter juris-
diction of the District Court”); id. at 2728 (Kennedy, J., concurring)
(“Because the immediate-custodian and territorial-jurisdiction rules are
like personal jurisdiction or venue rules, objections to the filing of peti-
tions based on those grounds can be waived by the Government.”); see
also Smith v. Idaho, 392 F.3d 350, 354-56 (9th Cir. 2004).
7662                  MUJAHID v. DANIELS
City of Long Beach, 241 F.3d 674, 678 (9th Cir. 2001). The
government has not met that burden.

   [2] An appeal is moot “when, by virtue of an intervening
event, a court of appeals cannot grant any effectual relief
whatever in favor of the appellant.” Calderon v. Moore, 518
U.S. 149, 150 (1996) (per curiam) (citation and internal quo-
tation marks omitted). Failure to satisfy Article III’s case-or-
controversy requirement renders a habeas petition moot.
Spencer v. Kemna, 523 U.S. 1, 7 (1998). “This means that,
throughout the litigation, the plaintiff must have suffered, or
be threatened with, an actual injury traceable to the defendant
and likely to be redressed by a favorable judicial decision.”
Id. (citation and internal quotation marks omitted).

   The government argues that we are unable to provide any
relief to Mujahid because he completed his term of imprison-
ment and was placed on supervised release. The government
relies on United States v. Johnson, 529 U.S. 53, 54 (2000), to
support its position. We agree that Johnson holds that a pris-
oner who wrongfully serves excess prison time is not entitled
to an automatic reduction in his term of supervised release. Id.
at 60. But our post-Johnson precedent does not support con-
struing Johnson in the manner advocated by the government.

   [3] We addressed this very issue in Gunderson v. Hood,
268 F.3d 1149, 1153 (9th Cir. 2001). Although the petitioner
in Gunderson challenged an agency practice affecting the
length of his sentence, we recognized that the court was
unable to order any reduction in prison time because he would
not be eligible for such relief until his term of imprisonment
expired. We held this fact did not render the petition moot,
however, because the petitioner’s sentence included a term of
supervised release. The “possibility” that the sentencing court
would use its discretion to reduce a term of supervised release
under 18 U.S.C. § 3583(e)(2) was enough to prevent the peti-
tion from being moot. Id.; see also United States v. Verdin,
243 F.3d 1174, 1178 (9th Cir. 2001) (holding a defendant on
                          MUJAHID v. DANIELS                          7663
supervised release retained a personal stake in the appeal of
his sentence because, if he prevailed, “he could be resen-
tenced to a shorter period of supervised release”).

   [4] Gunderson controls our mootness inquiry. There “is a
possibility” that Mujahid could receive a reduction in his term
of supervised release under 18 U.S.C. § 3583(e)(2). 253 F.3d
at 1153. Gunderson does not require more.

   The government’s attempt to distinguish Gunderson is
unavailing. The government maintains that the Gunderson
petitioner, unlike Mujahid, sought habeas relief in the same
court in which he was originally sentenced. This supposed
fact allegedly differentiates Gunderson because Mujahid’s
habeas court (in the District of Oregon) has no control over
the decision to modify the supervised release terms, which
rest with the sentencing court (in the District of Alaska).

   We cannot accept this argument. Gunderson, like Mujahid,
followed general habeas procedure in naming as respondent
the warden of the prison where he was incarcerated at the
time of filing his petition. Gunderson, 268 F.3d at 1152-53;
see also Padilla, 124 S. Ct. at 2720. The Gunderson opinion
does not state that the petitioner was seeking habeas relief
before the same court in which he was sentenced, and there
is no indication that its mootness analysis turned on such a
fortuitous occurrence.3
  3
    We note another potential flaw in the government’s argument. Under
even the government’s interpretation of Gunderson, this petition would
not be moot in Mujahid’s sentencing court in the District of Alaska. See
268 F.3d at 1153. The government has not explained why an appellate
court in our position could not order Mujahid’s petition transferred to that
court, if we were so inclined. See, e.g., Gherebi v. Bush, 374 F.3d 727, 739
(9th Cir. 2004) (“exercising jurisdiction” over habeas petition and “trans-
ferring the proceedings to the appropriate forum,” citing district court
transfer of venue statutes, 28 U.S.C. §§ 1404, 1406).
7664                     MUJAHID v. DANIELS
                                   C

   [5] Mujahid filed his habeas petition in the proper district
court, naming the proper respondent. See Padilla, 124 S. Ct.
at 2718. He remains in “custody” for habeas purposes. Matus-
Leva, 287 F.3d at 761. His petition asserts an injury due to the
duration of his sentence and seeks relief through a possible
reduction of his term in custody. Gunderson, 268 F.3d at
1153. This appeal is properly before us and is not moot.

                                   III

   We now turn to the merits of Mujahid’s challenge to the
BOP’s interpretation of the federal good time statute, 18
U.S.C. § 3624(b). Mujahid asserts that the BOP’s interpreta-
tion erroneously reduces the amount of good time credit avail-
able on a ten-year sentence from 540 to 470 days. Although
Mujahid’s reading of the statute is arguably plausible, we
have previously held that the BOP’s contrary interpretation is
reasonable and subject to deference. Pacheco-Camacho v.
Hood, 272 F.3d 1266, 1270 (9th Cir. 2001). This determina-
tion is controlling.

                                   A

   [6] At issue in this appeal is the 19954 version of 18 U.S.C.
§ 3624(b)(1), which states in relevant part (emphasis added):

      (b) Credit toward service of sentence for satisfac-
      tory behavior.—

      (1) A prisoner . . . who is serving a term of impris-
      onment of more than one year, other than a term of
      imprisonment for the duration of the prisoner’s life,
  4
   We quote from the version of this statute in effect in 1995, when
Mujahid was convicted. Both parties agree that this version of the statute
controls for purposes of Mujahid’s appeal.
                         MUJAHID v. DANIELS                         7665
      shall receive credit toward the service of the prison-
      er’s sentence, beyond the time served, of fifty-four
      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, unless the Bureau of Prisons deter-
      mines that, during that year, the prisoner has not sat-
      isfactorily complied with . . . institutional
      disciplinary regulations. . . . The Bureau’s determi-
      nation [of satisfactory compliance] shall be made
      within fifteen days after the end of each year of the
      sentence. Credit that has not been earned may not
      later be granted. Credit 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 sen-
      tence.

  The Bureau and Mujahid disagree on whether “term of
imprisonment” as used in the italicized portion of the statute
means time actually served (BOP interpretation) or sentence
imposed (Mujahid interpretation). The BOP implementing
regulation provides:

      Pursuant to 18 U.S.C. 3624(b), as in effect for
      offenses committed on or after November 1, 1987
      but before April 26, 1996, an inmate earns 54 days
      credit toward service of sentence (good conduct time
      credit) for each year served. This amount is prorated
      when the time served by the inmate for the sentence
      during the year is less than a full year.

28 C.F.R. § 523.20 (emphasis added).5

  [7] In accordance with this regulation and the Bureau’s
applicable Program Statement, a prisoner does not “earn”
  5
    Mujahid waived any possible argument about this regulation’s applica-
bility to Mujahid’s sentence by not raising the issue in his briefing. See
United States v. Kama, 394 F.3d 1236, 1238 (9th Cir. 2005).
7666                     MUJAHID v. DANIELS
good time credit until after serving that time. See Federal
Bureau of Prisons Program Statement 5880.28 (Feb. 21,
1992). To earn 54 days of credit, a prisoner must first com-
plete 365 days of incarceration. The BOP prorates awards
during the last year that a prisoner is incarcerated, awarding
0.148 days credit [54/365 = 0.148] per day actually served
that year. See Pacheco-Camacho, 272 F.3d at 1267-1268.

   Under these calculations, Mujahid accumulated 432 days of
credit over eight years [(54 days/year) x (8 years) = 432].
Because Mujahid had enough credit to qualify for release dur-
ing his ninth year in prison, the BOP prorated the amount of
credit he could earn that partial year, awarding 38 days.
Mujahid received no credit for the tenth year of his sentence,
when he was not in prison.

   Mujahid, in contrast, reads this statute as awarding good
time credit based on the sentence imposed. Using the straight-
forward calculation of 54 days per year multiplied by ten
years, Mujahid argues that he was entitled to 540 days of
credit. To avoid awarding credit for time not served, Mujahid
essentially starts counting toward the next “year” of imprison-
ment every 311 days.6

   The end result is that, over a ten-year sentence, Mujahid’s
interpretation enables a prisoner to earn 70 more days of
credit than allowed by the BOP.

                                    B

  This dispute turns on whether we accept the BOP’s inter-
  6
   As Mujahid calculates the good time credit, the “year of the prisoner’s
term of imprisonment” ends once the number of days served plus the good
time credit for that year equals 365. In other words, one year ends after
approximately 311 days (365-54); two years after 622 days [(365 x 2) -
(54 x 2)], and ten years after 3,112 days [(365 x 10) - (54 x 10)] (Leap
years excluded).
                      MUJAHID v. DANIELS                    7667
pretation of the phrase “term of imprisonment” to mean “time
served.” “Because this case involves an administrative agen-
cy’s construction of a statute that it administers, our analysis
is governed by Chevron U.S.A. Inc. v. Natural Resources
Defense Council, Inc., 467 U.S. 837 (1984).” Food and Drug
Admin. v. Brown & Williamson Tobacco Corp., 529 U.S. 120,
132 (2000); accord Pacheco-Camacho, 272 F.3d at 1268.
Under the Chevron framework, a reviewing court first deter-
mines if “ ‘Congress has directly spoken to the precise ques-
tion at issue,’ in such a way that ‘the intent of Congress is
clear.’ ” Pacheco-Camacho, 272 F.3d at 1268 (quoting Chev-
ron, 467 U.S. at 842). If the statute is silent or ambiguous, the
court decides “whether the agency’s interpretation ‘is based
on a permissible construction of the statute.’ ” Id. (quoting
Chevron, 467 U.S. at 843).

   [8] In Pacheco-Camacho, we held that the BOP’s interpre-
tation of 18 U.S.C. § 3624(b) is entitled to full Chevron defer-
ence. At issue in Pacheco-Camacho was the BOP’s policy for
prorating the good time credit of a prisoner sentenced to one
year plus a day imprisonment. We first determined that the
phrase “term of imprisonment” as used in § 3624(b) is ambig-
uous, observing that to read “term of imprisonment” as “sen-
tence imposed” would be inconsistent with a statute that
contemplates prorating credit for the last year of imprison-
ment. Id. at 1268. We also concluded that the Bureau’s inter-
pretation was supported by legislative history indicating an
attempt to “strike a balance between simplicity and fairness”
by calculating credits in a consistent manner and prorating
credits to ensure that those who served more time were eligi-
ble for more credit. Id. at 1270. We relied on these same rea-
sons to hold that the BOP’s interpretation of “term of
imprisonment” as “time served” was reasonable. Id. at 1271.

   [9] Mujahid’s interpretation of § 3624(b)    is at odds with
Pacheco-Camacho’s holding that the BOP’s        interpretation is
reasonable and subject to deference. We          are bound by
Pacheco-Camacho’s holding unless (1) the        issue presented
7668                  MUJAHID v. DANIELS
here is sufficiently distinguishable or (2) binding authority
casts sufficient doubt on the validity of Pacheco-Camacho’s
analysis to allow us to disregard its reasoning. We are uncon-
vinced on both fronts.

                               1

   Mujahid’s attempts to distinguish Pacheco-Camacho are
unpersuasive. Mujahid would limit Pacheco-Camacho to
solely addressing the meaning of “term of imprisonment” as
it relates to prorating credits during the last year of a prison-
er’s sentence. He asserts that his petition differs because he
challenges the BOP’s calculation of good time credits overall.
But so did Pacheco-Camacho. In fact, Pacheco-Camacho
made the same argument and used the same provision for sup-
port. Like Mujahid, Pacheco-Camacho argued that “when the
statute awards fifty-four days ‘at the end of each year of the
prisoner’s term of imprisonment,’ this award should be based
on the sentence imposed, without regard to the time actually
served.” Id. at 1268. Our rejection of Pacheco-Camacho’s
position indicates that our holding was not as limited as
Mujahid contends.

   Mujahid’s assertion that Pacheco-Camacho controls the
meaning of “term of imprisonment” only in the context of
prorating credit is problematic for another reason as well.
Under even this most narrow reading of Pacheco-Camacho,
that decision still holds that the BOP’s interpretation of “term
of imprisonment” in the last sentence of § 3624 as “time
served” is reasonable. See id. at 1270-71. Mujahid does not
explain how, given this precedent, interpreting “term of
imprisonment” differently (i.e., as “sentence imposed”) earlier
in the same statute is any more consistent with rules of intra-
statutory interpretation than the interpretation given by the
Bureau.
                          MUJAHID v. DANIELS                         7669
                                    2

   Besides attempting to limit the reach of Pacheco-Camacho,
Mujahid argues that subsequent Supreme Court cases have
undermined Pacheco-Camacho’s “mode of reasoning.”
Mujahid asserts that recent cases suggest that Pacheco-
Camacho erred in not applying the rule of lenity before apply-
ing Chevron deference. For one three-judge panel to disregard
prior binding authority, “the relevant court of last resort must
have undercut the theory or reasoning underlying the prior
circuit precedent in such a way that the cases are clearly irrec-
oncilable.” Miller v. Gammie, 335 F.3d 889, 900 (9th Cir.
2003). Mujahid has not persuaded us that we are faced with
such a situation here.7

   [10] Pacheco-Camacho holds that the rule of lenity “does
not prevent an agency from resolving statutory ambiguity
through a valid regulation.” 272 F.3d at 1271. We cited
Supreme Court precedent for support. See Babbitt v. Sweet
Home Chapter of Cmtys. for a Great Oregon, 515 U.S. 687,
704 n.18 (1995) (“We have never suggested that the rule of
lenity should provide the standard for reviewing facial chal-
lenges to administrative regulations whenever the governing
statute authorizes criminal enforcement.”). We explained that
our decision comported with the rule’s purpose as well. Spe-
cifically, the rule of lenity is designed to “ensure[ ] that the
penal laws will be sufficiently clear, so that individuals do not
accidentally run afoul of them and courts do not impose pro-
hibitions greater than the legislature intended.” Pacheco-
Camacho, 272 F.3d at 1271. Regulations such as the one at
issue here “gives the public sufficient warning to ensure that
  7
   See also O’Donald v. Johns, 402 F.3d 172, 174 (3d Cir. 2005) (per
curiam) (citing Pacheco-Camacho in rejecting petitioner’s rule of lenity
analysis); Perez-Olivio v. Chavez, 394 F.3d 45, 53 (1st Cir. 2005) (reject-
ing rule of lenity argument); but cf. Dolfi v. Pontesso, 156 F.3d 696, 700
(6th Cir. 1998) (declining to apply Chevron deference to a Parole Com-
mission interpretation of a different statute).
7670                  MUJAHID v. DANIELS
nobody mistakes the ambit of the law or its penalties.” Id. at
1272. We also noted that the Supreme Court has applied
Chevron deference in construing another BOP-administered
statute affecting prison terms. See id. (citing Lopez v. Davis,
531 U.S. 230, 242 (2001)).

   [11] We cannot say that binding authority has “undercut”
this analysis. By collecting assorted passages from recent
Supreme Court opinions, Mujahid creates an argument that is
tenuous at best and requires us to fill in more blanks than we
are willing to do. In particular, neither Leocal v. Ashcroft, 125
S. Ct. 377 (2004), nor Clark v. Martinez, 125 S. Ct. 716
(2005), address the relationship of Chevron deference to the
rule of lenity. Rather, both cases reference the rule of lenity
in dicta concerning unrelated points. See Leocal, 125 S. Ct. at
384 n.8 (stating that “consistency” requires applying the rule
of lenity to a statute that has both criminal and noncriminal
applications); Clark, 125 S. Ct. at 724 (citing the reference to
the rule of lenity in Leocal and United States v. Thompson/
Center Arms Co., 504 U.S. 505, 517-18 and n.10 (1992) (plu-
rality opinion), in stating that the “lowest common denomina-
tor” governs when construing statutory language with more
than one application).

   The language cited in these cases supports that the rule of
lenity can play an important role in statutory construction; it
does not address when the rule of lenity takes priority over
Chevron deference. And, ultimately, it is the answer to this
question that Mujahid must convince us has been provided, or
most assuredly would be provided, by the Supreme Court in
a manner “irreconcilable” with Pacheco-Camacho. The cases
relied on by Mujahid do not do so.

                               IV

   Pacheco-Camacho established that the phrase “term of
imprisonment” in 18 U.S.C. § 3624(b)(1) is ambiguous, that
the BOP’s interpretation was reasonable, and is thus entitled
                           MUJAHID v. DANIELS                          7671
to deference. Mujahid’s position rests on an interpretation of
this statute at odds with binding authority of this court.8

   AFFIRMED.




  8
    Mujahid fashioned his initial filing before this panel as both an opening
brief and a petition for initial hearing en banc, should we conclude that
Pacheco-Camacho is controlling. Our denial of Mujahid’s petition on the
present record is without prejudice to review on a timely basis.
