                               In the

    United States Court of Appeals
                 For the Seventh Circuit
                     ____________________
No. 17-1439
JESUS ARREOLA-CASTILLO,
                                                Petitioner-Appellant,

                                 v.

UNITED STATES OF AMERICA,
                                               Respondent-Appellee.
                     ____________________

         Appeal from the United States District Court for the
         Southern District of Indiana, Indianapolis Division.
            No. 14-cv-2118 — Larry J. McKinney, Judge.
                     ____________________

       ARGUED APRIL 10, 2018 — DECIDED MAY 3, 2018
                     ____________________

   Before WOOD, Chief Judge, and FLAUM and KANNE, Circuit
Judges.
    FLAUM, Circuit Judge. Petitioner Jesus Arreola-Castillo was
convicted of a federal drug crime. Because he had at least two
prior felony drug convictions in New Mexico, he was subject
to the recidivism provisions of 21 U.S.C. § 841. Pursuant to
that statute, he received a mandatory minimum sentence of
life in prison. He subsequently challenged the underlying fel-
ony drug convictions in New Mexico state court, which the
2                                                     No. 17-1439

state court ultimately vacated. Now, he moves to reopen his
federal sentence under 28 U.S.C. § 2255, arguing that he is no
longer subject to the recidivism enhancement because the
prior state convictions have been vacated. The district court
denied his § 2255 petition on the ground that it was time-
barred. It relied on 21 U.S.C. § 851(e), which prohibits an in-
dividual from challenging the validity of a prior conviction
that is more than five years old at the time the government
seeks the recidivism enhancement. Because Arreola-Castillo
is not challenging the validity of his prior convictions, but ra-
ther their very existence, we reverse.
                           I. Background
     In 2006, a jury found Arreola-Castillo guilty of conspiracy
to distribute 1,000 kilograms or more of marijuana in violation
of 21 U.S.C. §§ 841(a)(1) and 846. The government filed two
informations under 21 U.S.C. § 851 alleging that Arreola-Cas-
tillo had previously been convicted of two felony drug of-
fenses in New Mexico in 1996. Because he had two or more
prior felony drug convictions, the district court was required
to impose a mandatory life sentence under the recidivism pro-
visions of 21 U.S.C. § 841(b)(1)(A). Had it not been for the
mandatory life sentence, Arreola-Castillo’s Guidelines sen-
tencing range would have been 188–235 months in prison. We
affirmed Arreola-Castillo’s sentence on direct appeal in 2008.
See United States v. Arreola-Castillo, 539 F.3d 700 (7th Cir. 2008).
    Arreola-Castillo subsequently challenged both underlying
state convictions in New Mexico state courts. He moved to
withdraw the guilty pleas in those convictions on the ground
that he received ineffective assistance of counsel. Specifically,
Arreola-Castillo claimed that his attorney did not inquire into
No. 17-1439                                                   3

his immigration status or sufficiently advise him of the immi-
gration consequences of pleading guilty. The New Mexico
state courts agreed and accordingly vacated the convictions
on November 19, 2014 and June 29, 2015.
    In December 2014, after his first conviction was vacated,
Arreola-Castillo moved to reopen his federal sentence under
§ 2255. The government initially moved to dismiss the peti-
tion as an unauthorized second or successive petition under
28 U.S.C. §§ 2244 and 2255(h). The court denied that motion,
ruling that Arreola-Castillo’s petition was based on a claim
that did not become ripe until his state convictions were va-
cated.
    Next, the government argued that Arreola-Castillo’s claim
was “meritless” in light of 21 U.S.C. § 851(e). That provision
bars an individual from “challeng[ing] the validity of any
prior conviction alleged under this section which occurred
more than five years before the date of the information alleg-
ing such prior conviction.” 21 U.S.C. § 851(e). The govern-
ment argued that § 851(e) precludes Arreola-Castillo’s claim
because the informations alleging the prior convictions were
filed in 2006—more than five years after his (now vacated)
convictions occurred in 1996. In response, Arreola-Castillo ar-
gued that § 851(e), which assumes the existence of a prior con-
viction and addresses its validity, does not apply because his
convictions have been vacated.
     In January 2017, the district court held that § 851(e) bars
Arreola-Castillo’s claims, and accordingly denied his petition
for relief under § 2255. We subsequently granted Arreola-Cas-
tillo’s request for a certificate of appealability. Although the
parties had not addressed the issue below, we instructed them
4                                                    No. 17-1439

to brief the timeliness of Arreola-Castillo’s claim under
§ 2255(f)(4).
                           II. Discussion
    “On an appeal from the denial of a § 2255 motion, we re-
view the district court’s legal conclusions de novo and its fac-
tual findings for clear error.” Keller v. United States, 657 F.3d
675, 679 (7th Cir. 2011). “A § 2255 motion must be granted
when a defendant’s ‘sentence was imposed in violation of the
Constitution or laws of the United States.’” Fountain v. United
States, 211 F.3d 429, 433 (7th Cir. 2000) (quoting 28 U.S.C.
§ 2255)).
    A. We Decline to Address the Government’s Forfeited
       Timeliness Argument Under § 2255(f)(4)
     There is a one-year statute of limitations for filing habeas
petitions. 28 U.S.C. § 2255(f). In relevant part, the limitation
period runs from “the date on which the facts supporting the
claim or claims presented could have been discovered
through the exercise of due diligence.” Id. § 2255(f)(4). In John-
son v. United States, the Supreme Court held that vacatur of a
prior state conviction used to enhance a federal sentence is a
“matter of fact” that could trigger this one-year limitation pe-
riod. 544 U.S. 295, 302 (2005). “[T]he period begins when a pe-
titioner receives notice of the order vacating the prior convic-
tion, provided that he has sought it with due diligence in state
court, after entry of judgment in the federal case with the en-
hanced sentence.” Id. at 298.
   On appeal, the government argues for the first time that
Arreola-Castillo’s petition is untimely under § 2255(f)(4) be-
No. 17-1439                                                             5

cause he did not diligently pursue vacatur of his state convic-
tions. 1 Despite two years of litigation below, the government
never made this timeliness argument in the district court. In-
stead, it moved to dismiss Arreola-Castillo’s petition on the
ground that it was an unauthorized successive motion under
§§ 2244 and 2255(h). When that failed, the government argued
that § 851(e) barred Arreola-Castillo’s challenge.
    We are not required to address the government’s belated
timeliness argument. The statute of limitations in § 2255(f)(4)
is not a jurisdictional requirement, but rather an affirmative
defense. Estremera v. United States, 724 F.3d 773, 775 (7th Cir.
2013). As a general rule, a defendant must raise a statute of
limitations defense in their answer. Day v. McDonough, 547
U.S. 198, 207–08 (2006) (citing Fed. R. Civ. P. 8(c), 12(b), 15(a)).
Failure to do so results in forfeiture. Id. Accordingly, “courts
are under no obligation to raise the time bar sua sponte.” Id. at
205.
    Nevertheless, we have discretion to examine the timeli-
ness of a habeas petition “when extraordinary circumstances
so warrant.” Wood v. Milyard, 566 U.S. 463, 471, 473 (2012) (cit-
ing Day, 547 U.S. at 201). “[L]eeway” is appropriate in this
context because the statute of limitations “implicat[es] values
beyond the concerns of the parties.” Id. at 472 (second altera-
tion in original) (quoting Day, 547 U.S. at 205). It “promotes
judicial efficiency and conservation of judicial resources, safe-
guards the accuracy of state court judgments by requiring res-
olution of constitutional questions while the record is fresh,


    1  The government does not dispute that Arreola-Castillo filed his
§ 2255 petition within one year of receiving notice of the orders vacating
his state convictions.
6                                                    No. 17-1439

and lends finality to state court judgments within a reasona-
ble time.” Id. (quoting Day, 547 U.S. at 205–06). Although Day
and Wood involved state prisoners’ habeas petitions under 28
U.S.C. § 2244, we have assumed that those cases apply equally
to federal prisoners’ habeas petitions under § 2255. See, e.g.,
Ryan v. United States, 688 F.3d 845, 848 (7th Cir. 2012).
    This discretion is limited in several important respects.
First and foremost, “a federal court does not have carte blanche
to depart from the principle of party presentation basic to our
adversary system.” Wood, 566 U.S. at 472. Thus, although we
may consider a timeliness argument that was inadvertently
forfeited, “[i]t would be ‘an abuse of discretion … to override
a State’s deliberate waiver of a limitations defense.’” Id. at
472–73 (quoting Day, 547 U.S. at 202). In other words, “a court
of appeals is entitled to deny collateral relief on a procedural
ground that the prosecutor has forfeited by overlooking it, but
not on a ground that the prosecutor has waived.” Ryan, 688
F.3d at 848.
     Second, even if the government accidentally forfeits a
timeliness argument, our “power to decide an appeal on a for-
feited ground should be used only in exceptional cases.” Id.
We have “good reason” to “abstain from entertaining issues
that have not been raised and preserved in the court of first
instance.” Wood, 566 U.S. at 473. “That restraint is all the more
appropriate when the appellate court itself spots an issue the
parties did not air below.” Id. In addition, we must give “[d]ue
regard for the trial court’s processes and time investment.” Id.
After all, “[i]t typically takes a district court more time to de-
cide a habeas case on the merits, than it does to resolve a pe-
tition on threshold procedural grounds.” Id. When a court of
appeals belatedly interjects a procedural impediment after
No. 17-1439                                                       7

resolution on the merits, “the district court’s labor is dis-
counted.” Id. at 474. Perhaps even more troubling, “the appel-
late court acts not as a court of review but as one of first view.”
Id.
   Here, the government argues that its failure to pursue a
timeliness argument under § 2255(f)(4) was an unintentional
“misstep.” Accordingly, it contends that it merely forfeited
the argument. Arreola-Castillo, on the other hand, argues for
waiver. In the event we find forfeiture, Arreola-Castillo ar-
gues that we should not exercise our discretion to address the
timeliness issue.
    Ultimately, we need not decide the issue. Even if the gov-
ernment merely forfeited the timeliness argument, we would
not exercise our discretion to address it sua sponte. The gov-
ernment does not cite a single case in which we have exercised
our discretion to address a forfeited timeliness argument in a
habeas case on appeal. We have, however, declined to exercise
that discretion on at least two occasions. See Turner v. United
States, 693 F.3d 756, 758–59 (7th Cir. 2012); Hill v. Werlinger, 695
F.3d 644, 647 (7th Cir. 2012). As in those cases, the government
“has presented nothing to show that this is an ‘exceptional
case’ in which we should base our decision on a forfeited
ground.” Hill, 695 F.3d at 647 (quoting Wood, 566 U.S. at 473).
The government argues that the record already contains the
relevant facts. But that hardly renders this case exceptional.
Furthermore, Arreola-Castillo might have submitted addi-
tional evidence of his diligence had the government raised the
timeliness objection in the district court. We decline to penal-
ize him now for substantiating his claims despite the govern-
ment’s oversight. The government also claims that we should
8                                                    No. 17-1439

exercise our discretion to “avoid a potentially difficult statu-
tory construction question with a lurking circuit split behind
it.” However, as explained infra, the only published federal
court of appeals decision on this issue favors Arreola-Cas-
tillo’s interpretation. And even if we took the other circuit’s
nonprecedential order into account, we would at most be lin-
ing up on one side of a debate. In this context, we see no rea-
son to avoid such a step.
    In sum, we have good reason to exercise our normal re-
straint in this context. The district court presided over this
case for two years and ultimately resolved it on the merits.
Were we to dismiss the case on a procedural ground at this
juncture, we would effectively discount the district court’s ef-
forts. Therefore, we exercise our discretion to proceed to the
merits of Arreola-Castillo’s habeas petition.
    B. Section 851(e) Does Not Apply to a § 2255 Petition to
       Reopen a Federal Sentence Based on the Vacatur of
       Enhancing State Convictions
    Turning to the merits, Arreola-Castillo argues that the dis-
trict court erred by holding that § 851(e) bars an individual
from reopening his federal sentence under § 2255 when the
state convictions that enhanced the sentence have since been
vacated. We review that question of statutory interpretation
de novo. United States v. Ford, 798 F.3d 655, 661 (7th Cir. 2015).
       1. Statutory Framework
    Section 841(b) outlines the penalties for federal drug
crimes based upon the quantity of drugs involved and the
number of prior drug convictions. See 21 U.S.C. § 841(b).
When a drug offense involves 1,000 kilograms or more of ma-
rijuana, the statutory sentencing range is ten years to life in
No. 17-1439                                                      9

prison. Id. § 841(b)(1)(A). If the defendant has two or more
prior convictions for a felony drug offense, the penalty be-
comes a mandatory life sentence. Id.
    To impose a recidivism penalty under § 841, the govern-
ment must follow the procedures in 21 U.S.C. § 851. Under
that section, the United States attorney must file an infor-
mation with the sentencing court stating the previous convic-
tions to be relied upon. Id. § 851(a). If an information is filed,
“the court shall … inquire of the person with respect to whom
the information was filed whether he affirms or denies that he
has been previously convicted as alleged in the information.”
Id. § 851(b). “If the person denies any allegation of the infor-
mation of prior conviction, or claims that any conviction al-
leged is invalid, he shall file a written response … .” Id.
§ 851(c)(1). “Any challenge to a prior conviction, not raised by
response to the information before an increased sentence is
imposed in reliance thereon, shall be waived unless good
cause be shown for failure to make a timely challenge.” Id.
§ 851(c)(2).
    If the person files a response, “[t]he court shall hold a hear-
ing to determine any issues raised by the response which
would except the person from increased punishment.” Id.
§ 851(c)(1). At the hearing, the parties may present evidence
and request that the court make findings of fact and conclu-
sions of law. Id. “If the court determines that the person has
not been convicted as alleged in the information, that a con-
viction alleged in the information is invalid, or that the person
is otherwise not subject to an increased sentence as a matter
of law,” the United States attorney may appeal that determi-
nation. Id. § 851(d).
10                                                   No. 17-1439

    Section 851 also includes the following statute of limita-
tions: “No person who stands convicted of an offense under
this part may challenge the validity of any prior conviction
alleged under this section which occurred more than five
years before the date of the information alleging such prior
conviction.” Id. § 851(e).
       2. The Statutory Text Distinguishes Between Challenging
          the Validity of a Prior Conviction and Disputing the Fact
          of a Prior Conviction
     The parties dispute whether the five-year statute of limita-
tions in § 851(e) applies to Arreola-Castillo’s § 2255 petition.
The answer to this question turns on whether Arreola-Cas-
tillo’s habeas petition “challenge[s] the validity of any prior
conviction.” Id. If so, it is clearly barred by § 851(e) because
the government filed the information alleging his prior con-
victions in 2006—more than five years after the prior convic-
tions occurred in 1996. However, Arreola-Castillo argues that
because the state court already vacated his prior convictions,
he is no longer challenging the validity of those convictions,
but rather their very existence. Accordingly, he claims that
§ 851(e) does not apply.
    To resolve this dispute, we must “begin[] with the plain
language of the statute.” United States v. Berkos, 543 F.3d 392,
396 (7th Cir. 2008). Here, the statutory language supports Ar-
reola-Castillo’s interpretation. Section 851 repeatedly distin-
guishes between denying the fact of a prior conviction, on the
one hand, and challenging the validity of a prior conviction,
on the other. For example, under § 851(c)(1), a person may re-
spond to an information by either “den[ying] any allegation
of the information of prior conviction, or claim[ing] that any
conviction alleged is invalid.” 21 U.S.C. § 851(c)(1). Likewise,
No. 17-1439                                                            11

under § 851(d)(2), the sentencing court may “determine[] that
the person has not been convicted as alleged in the infor-
mation, that a conviction alleged in the information is invalid,
or that the person is otherwise not subject to an increased sen-
tence as a matter of law.” Id. § 851(d)(2). The statute’s persis-
tent use of the disjunctive “or” when describing these con-
cepts suggests that denying the fact of a prior conviction and
challenging the validity of a prior conviction must be given
separate meanings. See Reiter v. Sonotone Corp., 442 U.S. 330,
339 (1979) (“Canons of construction ordinarily suggest that
terms connected by a disjunctive be given separate meanings
… .”). Critically, although § 851(e) bars an individual from
challenging “the validity of any prior conviction” that is more
than five years old, it in no way limits an individual’s ability
to deny that such a conviction exists. 21 U.S.C. § 851(e).
    In addition, § 851’s use of the word “challenge” is instruc-
tive. “The word ‘challenge’ is used only three other times in
§ 851, once in § 851(b) and twice in § 851(c)(2).” United States
v. McChristian, 47 F.3d 1499, 1503 (9th Cir. 1995). In § 851(b), it
is “ambiguous” whether the word “challenge” would include
a showing that the prior conviction has been vacated in state
court. Id. 2 However, the use of “challenge” in § 851(c)(2) pro-
vides more insight into what the drafters intended that word
to mean. See id. Section 851(c)(2) outlines the steps a defendant
must take if he “claim[s] that a conviction alleged in the infor-
mation was obtained in violation of the Constitution of the


    2 To the extent one could argue that §851(b) uses the term “challenge”
more broadly than § 851(c), at most that would suggest that there is some
ambiguity in the statute. The context and purpose of the law taken as a
whole, however, suggest that the word “challenge” normally means a
“full-blown attack,” for the reasons we have explained.
12                                                   No. 17-1439

United States.” 21 U.S.C. § 851(c)(2). In that scenario, the de-
fendant must “set forth his claim, and the factual basis there-
for, with particularity in his response to the information.” Id.
The provision also establishes the burden of proof (prepon-
derance of the evidence) with respect to any factual issues
raised in the response. Id. In the very next sentence, § 851(c)(2)
refers to this situation as a “challenge to a prior conviction.”
Id. The reference to pleading requirements and the burden of
proof suggests that the word “challenge,” as used in
§ 851(c)(2), “means only a full-blown, collateral attack in fed-
eral court on the prior conviction.” McChristian, 47 F.3d at
1503. It follows that “challenge” means the same in § 851(e).
See United States v. LaFaive, 618 F.3d 613, 617 (7th Cir. 2010)
(“Absent evidence of Congress’s intent to the contrary, we as-
sume that Congress intended the same words used close to-
gether in a statute to have the same meaning.”). Where, as
here, a state court has vacated the prior convictions, the peti-
tioner is not launching a full-blown collateral attack in the fed-
eral court. Rather, he has already successfully challenged the
validity of those convictions in state court and is simply ask-
ing the federal court to recognize the state court’s determina-
tion.
    Looking at § 851(e) in isolation, the government argues
that denying the existence of a vacated conviction necessarily
entails challenging the validity of that conviction. To support
this argument, the government points to various dictionary
definitions of the term “validity.” However, this argument
fails for two reasons.
   First, some of the proffered definitions of “validity”—e.g.,
“the quality or state of being valid”—are unhelpful tautolo-
No. 17-1439                                                     13

gies. Validity, Merriam-Webster Dictionary, http://www.mer-
riam-webster.com/dictionary/validity (last visited May 2,
2018). Other definitions—e.g., “the quality of being well-
grounded, sound, or correct” and “meritorious”—actually
support Arreola-Castillo’s position. Id..; Valid, Black’s Law
Dictionary (10th ed. 2014). If valid means meritorious, then a
vacated “conviction ha[s] no ‘validity’ that could be chal-
lenged,” and “any challenge in federal court to the validity of
that conviction would have been moot.” McChristian, 47 F.3d
at 1503.
    Second, by offering definitions of validity that are com-
pletely untethered from how that word is used elsewhere in
the statute, the government violates “the cardinal rule that a
statute is to be read as a whole.” King v. St. Vincent’s Hosp., 502
U.S. 215, 221 (1991). “[S]tatutes ‘should not be read as a series
of unrelated and isolated provisions.’” Gonzales v. Oregon, 546
U.S. 243, 273 (2006) (quoting Gustafson v. Alloyd Co., 513 U.S.
561, 570 (1995)). “[T]he meaning of statutory language, plain
or not, depends on context.” King, 502 U.S. at 221. As ex-
plained supra, § 851 repeatedly refers to the validity of a con-
viction and the fact of a conviction as separate and mutually
exclusive concepts. To the extent there is a conflict between
the use of the word “validity” in the statute and generic dic-
tionary definitions, the statutory characterization prevails. See
Cent. States, Se. & Sw. Areas Pension Fund v. Fulkerson, 238 F.3d
891, 895 (7th Cir. 2001) (“Statutory terms or words will be con-
strued according to their ordinary, common meaning unless
these are defined by the statute or the statutory context re-
quires a different definition.”).
    Finally, it is important to note that § 851(e) does not speak
of the ability to file a case attacking the prior conviction. It
14                                                 No. 17-1439

would be extraordinary for a federal statute to forbid a person
from going to state court and properly filing an action that the
state court is prepared to entertain. At the very least, one
would expect a clear statement from Congress that such a pro-
found interference with the state-court system was contem-
plated. Nothing in § 851(e) comes close to a clear statement
permitting the federal courts, in effect, to enjoin someone
from filing a motion for relief in state court. Cf. 28 U.S.C.
§ 2283. Our interpretation of the statute respects this im-
portant federalism concern.
       3. Our Precedent Further Supports This Interpretation of
          § 851(e)
    When interpreting a statutory phrase, we also “consult[]
any precedents or authorities that inform the analysis.” Kasten
v. Saint-Gobain Performance Plastics Corp., 563 U.S. 1, 7 (2011)
(quoting Dolan v. Postal Serv., 546 U.S. 481, 486 (2006)). Here,
our precedent reinforces the statute’s distinction between
challenging the validity of a prior conviction and denying the
existence of a prior conviction.
   For example, in United States v. Arango-Montoya, we held
that § 851(e) applies to the former but not the latter. 61 F.3d
1331, 1339 (7th Cir. 1995). The defendant in that case claimed
that his prior state conviction was invalid because it was the
result of an involuntary guilty plea. Id. at 1333. He maintained
that even if § 851(e) prevented him from collaterally attacking
the prior conviction because it was more than five years old,
the sentencing court was still required to follow the proce-
dural requirements in § 851(b) and (c). Id. at 1339. We held
that the sentencing court’s failure to follow those procedures
was “harmless” because § 851(e) barred the defendant from
challenging the validity of his prior conviction, anyway. Id.
No. 17-1439                                                    15

However, we held that the sentencing court still had to ask the
defendant whether he affirmed or denied the prior conviction
as required by § 851(b), “even if § 851(e) bars a collateral at-
tack on the prior conviction.” Id. We noted that this require-
ment is necessary because “it is always possible that the gov-
ernment was mistaken and there was no prior conviction, or
that the facts alleged in the government’s information of prior
conviction are incorrect.” Id. Therefore, under Arango-Mon-
toya, an individual may deny the existence of a prior convic-
tion even if the five-year statute of limitations in § 851(e) pre-
vents him from challenging the validity of that conviction.
    Similarly, in United States v. Elder, 840 F.3d 455 (7th Cir.
2016), we suggested that an individual may challenge the ex-
istence of a qualifying conviction without impermissibly chal-
lenging the validity of the prior conviction. In that case, the
government filed an information under § 851 alleging that the
defendant had two prior state convictions that involved fel-
ony drug offenses. Id. at 458. Both of those prior convictions
were more than five years old, and the defendant did not at-
tempt to challenge their validity at sentencing. Id. Pursuant to
the recidivism provisions of § 841, the sentencing court im-
posed a mandatory life sentence of imprisonment. Id. On ap-
peal, the defendant argued that one of the prior convictions
“was not a conviction for a felony drug offense” within the
meaning of § 841 “because it was not punishable by more than
one year imprisonment.” Id. at 461. We agreed and accord-
ingly vacated the defendant’s mandatory life sentence. Id.
Even though the prior conviction was more than five years
old, we did not address whether § 851(e) barred the defend-
ants claim. Presumably, we did not need to because the de-
fendant was not challenging the validity of the prior convic-
tion.
16                                                  No. 17-1439

       4. Two of Our Sister Circuits Have Adopted This Interpre-
          tation of § 851(e)
    Our sister circuits have reached similar conclusions. In
McChristian, the Ninth Circuit held that § 851(e) did not pre-
clude the defendant from claiming that his prior conviction,
which was more than five years old, had been stricken by the
state court. 47 F.3d at 1503. The Ninth Circuit reached this con-
clusion for several reasons. First, the court noted that, because
the state court struck the prior conviction, “any challenge in
federal court to the validity of that conviction would have
been moot.” Id. Second, based on “a careful reading of the
statute,” the court concluded that “§ 851(e)’s purpose was to
exclude from federal court only collateral challenges to con-
victions and not reports of successful collateral challenges
completed in state court.” Id. In particular, the court relied on
how the word “challenge” is used in § 851. Id. Finally, the
court explained that, because the defendant’s prior conviction
was stricken before his federal sentencing, any concerns about
finality were “inapposite.” Id. Indeed, the court could “think
of no government interest in enhancing a defendant’s sen-
tence based on a prior conviction that has already been shown
to be obtained in violation of the Constitution.” Id.
    More recently, the Second Circuit also suggested in an un-
published decision that there is a distinction between chal-
lenging the fact of a conviction and the validity of a conviction
under § 851. In United States v. Gabriel, the defendant claimed
that the district court procedurally erred by failing to ask
whether he affirmed or denied his prior conviction. 599 F.
App’x 407, 407 (2d Cir. 2015). The defendant sought, but did
not achieve, vacatur of the prior conviction in state court. Id.
at 408. Because the defendant did not dispute the fact of his
No. 17-1439                                                   17

prior conviction, the Second Circuit held that he was not prej-
udiced by the alleged procedural error. Id. The court further
noted that the defendant “could not challenge the validity (as
opposed to the fact) of his prior felony conviction because it
occurred more than five years before the filing of the prior fel-
ony information.” Id. (citing 21 U.S.C. § 851(e)). Although the
Second Circuit did not address the precise issue presented
here, it intimated that a defendant may dispute the fact of a
prior conviction even if § 851(e) barred the defendant from
challenging its validity.
    Only the Eleventh Circuit, also in an unpublished deci-
sion, has reached the opposite conclusion. See St. Preux v.
United States, 539 F. App’x 946 (11th Cir. 2013) (per curiam). In
St. Preux, the court held that § 851(e) barred a federal prisoner
from reopening his federal sentence after the state court va-
cated the prior conviction that enhanced his federal sentence.
Id. at 948. The court stated that “the plain language” of
§ 851(e) barred the prisoner’s claim because the prior convic-
tion occurred more than five years before the government
filed its information. Id. It distinguished the Ninth Circuit’s
decision in McChristian because, in that case, the prior convic-
tion was vacated prior to the federal sentencing hearing. Id. at
949. Although the timing in McChristian diminished the final-
ity interests at stake, the Ninth Circuit focused primarily on
“a careful reading of the statute,” in particular § 851’s use of
the word “challenge.” McChristian, 47 F.3d at 1503. The St.
Preux court did not even attempt to grapple with this statu-
tory interpretation question. Nor did it provide any other rea-
soning for its conclusion. Accordingly, we do not find it per-
suasive.
18                                                            No. 17-1439

         5. The Government’s Negative Implications Argument Is
            Not Convincing
    Lacking support from the statutory text and case law, the
government argues that negative implications from other
statutes and the Sentencing Guidelines support its interpreta-
tion. Another recidivism statute—the Armed Career Criminal
Act of 1984 (“ACCA”) 3—provides that “[a]ny conviction
which has been expunged, or set aside or for which a person
has been pardoned or has had civil rights restored shall not
be considered a conviction for purposes of this chapter.” 18
U.S.C. § 921(a)(20). Similarly, the Sentencing Guidelines ex-
pressly preclude consideration of vacated convictions when
calculating a defendant’s criminal history or determining
whether they are a career offender. See U.S.S.G. § 4A1.2 cmt.
n.6. Because both the ACCA and Sentencing Guidelines ex-
plicitly exclude vacated convictions, the government argues
that Congress knows how to preclude courts from consider-
ing them when it so desires. Accordingly, the government
claims that the omission of similar language from § 851 sug-
gests that Congress intended to preclude all challenges to
prior convictions that are more than five years old, including
vacated convictions.
     This argument is unavailing. Indeed, the only authority
that has endorsed this negative implications argument is the
dissenting voice in McChristian. See 47 F.3d at 1509–10 (Hall,
J., dissenting in part). And the majority in that case found that
the statutory text compelled the opposite conclusion. See id. at


     3 The ACCA increases the penalty for possession of a firearm by a
felon if the defendant has prior convictions for a violent felony or a serious
drug offense. 18 U.S.C. § 924(e).
No. 17-1439                                                    19

1503. True, § 851(e) does not use the exact language found in
the ACCA. However, this is hardly surprising given that § 851
was enacted in 1970—almost sixteen years before the ACCA
was amended to prohibit consideration of vacated convic-
tions. See Pub. L. No. 91-513, 84 Stat. 1269 (codified at 21
U.S.C. § 851); Pub. L. No. 99-308, 100 Stat. 449 (codified at 18
U.S.C. § 921(a)(20)). Moreover, although we presume that
Congress acts intentionally when it “includes particular lan-
guage in one section of a statute but omits it another section
of the same Act,” that is not the case here. Russello v. United
States, 464 U.S. 16, 23 (1983) (quoting United States v. Wong Kim
Bo, 472 F.2d 720, 722 (1972)). Here, the government relies on
language used in a different federal statute to support its inter-
pretation of § 851(e). Accordingly, its negative implications ar-
gument is entitled to less weight. Finally, the government’s re-
liance on language in the Sentencing Guidelines is misplaced
because that language is written by the Sentencing Commis-
sion—an independent agency within the judicial branch—not
Congress. Therefore, the government’s attempt to glean con-
gressional intent based on language in the Sentencing Guide-
lines is unpersuasive.
    Ultimately, although § 851(e) does not use the same lan-
guage as the ACCA or the Sentencing Guidelines, it achieves
the same result by distinguishing between challenges to the
validity of a prior conviction and claims that a prior convic-
tion does not exist. Under the language of § 851 and our own
precedent interpreting that provision, the five-year statute of
limitations in § 851(e) applies to the former but not the latter.
       6. Section 851 Does Not Preclude Habeas Review
  Next, the government contends that § 851 is the “exclusive
means” for challenging prior convictions such that Arreola-
20                                                    No. 17-1439

Castillo may not use § 2255 as a vehicle to adjust his federal
sentence.
    In support of this argument, the government relies on
United States v. Roberson, 684 F. Supp. 2d 179 (D. Mass. 2010).
Like Arreola-Castillo, the defendant in Roberson filed a habeas
petition under § 2255 seeking to set aside his federal sentence
under 21 U.S.C. § 841 after a state court vacated the prior con-
viction that enhanced his sentence. Id. at 180–81. However, the
government argued that the defendant could not seek habeas
relief on that ground because § 851 provides the exclusive
procedure for challenging a prior conviction. Id. at 182. The
district court acknowledged that several Supreme Court cases
“generally support the proposition that an enhanced federal
sentence may be adjusted on a § 2255 motion after the enhanc-
ing prior conviction has been vacated.” Id. Nevertheless, the
court ultimately concluded that “Congress intended the pro-
visions of § 851 to provide the exclusive basis and procedures
for challenging such a prior conviction as it pertains to the en-
hancements for federal drug crimes authorized under
§ 841(b)(1)(A) and (B).” Id. at 189. This was so, the court ex-
plained, because the waiver provision in § 851(c)(2) does not
include an exception allowing an individual to later seek fed-
eral habeas relief under § 2255. Id. at 186. In addition, the court
reasoned that § 851(e)’s statute of limitations would “serve[]
no purpose” if an individual could later move for resentenc-
ing under § 2255. Id. at 187. Finally, the court interpreted the
“detailed provisions” in § 851(b) as “the equivalent of advice
to ‘speak now or forever hold your peace.’” Id. at 188. The
court conceded, however, that its “attempt to understand con-
gressional intent [was] indirect and inferential, and … thus
not a certain thing.” Id.
No. 17-1439                                                                 21

    In addition to being nonbinding on this Court, there is a
critical flaw in the Roberson court’s reasoning: “Implications
from statutory text or legislative history are not sufficient to
repeal habeas jurisdiction.” I.N.S. v. St. Cyr, 533 U.S. 289, 299
(2001). Rather, “Congress must articulate specific and unam-
biguous statutory directives to effect a repeal.” Id. Accord-
ingly, to the extent the government argues that § 851 pre-
cludes Arreola-Castillo from seeking habeas relief, it must
point to “a particularly clear statement that such is Congress’
intent.” Demore v. Kim, 538 U.S. 510, 517 (2003). The govern-
ment cannot do so here because § 851 does not even mention,
let alone expressly foreclose, either habeas relief under § 2255
or resort to a state court consistent with that court’s rules. See
21 U.S.C. § 851.
   Moreover, the Supreme Court has consistently held in
other statutory contexts that an individual may move to reo-
pen a federal sentence based on the state court’s vacatur of a
prior conviction that enhanced the sentence. For example, in
Custis v. United States, the Supreme Court held that, under the
ACCA, defendants may not collaterally attack the validity of
a prior conviction during a federal sentencing hearing. 511
U.S. 485, 490–94 (1994). 4 Nevertheless, although the ACCA
“[did] not permit [the defendant] to use the federal sentencing
forum to gain review of his state convictions,” the Court
noted that he “may attack his sentences in Maryland or
through federal habeas review.” Id. at 497. The Court contin-
ued: “If [the defendant] is successful in attacking these state


    4 The Court distinguished the ACCA from § 851, which allows an in-
dividual to challenge the validity of a prior conviction that is less than five
years old. See Daniels, 511 U.S. at 491.
22                                                            No. 17-1439

sentences, he may then apply for reopening of any federal
sentence enhanced by the state sentences.” Id.
    In Daniels v. United States, the Court reaffirmed that
“[a]fter an enhanced federal sentence has been imposed pur-
suant to the ACCA, the person sentenced may pursue any
channels of direct or collateral review still available to chal-
lenge his prior conviction,” including state court. 532 U.S. 374,
382 (2001). “If any such challenge to the underlying conviction
is successful, the defendant may then apply for reopening of
his federal sentence.” Id. 5
     Finally, in Johnson v. United States, the Court said that Cus-
tis and Daniels “assume[d] … that a defendant given a sen-
tence enhanced for a prior conviction is entitled to a reduction
if the earlier conviction is vacated.” 544 U.S. at 303. The John-
son court reiterated that “a defendant who successfully at-
tacked his state conviction in state court or on federal habeas
review could then ‘apply for reopening of any federal sen-
tence enhanced by the state sentences.’” Id. (quoting Custis,
511 U.S. at 497). Although these decisions involved the
ACCA, the government does not point to anything in § 851 to
support a contrary conclusion here.




     5 Unlike Arreola-Castillo, who successfully sought vacatur of his prior

convictions in state court, the petitioner in Daniels “failed to pursue reme-
dies that were otherwise available to him to challenge his [prior] convic-
tions.” 523 U.S. at 384. Having failed to do so, the Court held that he could
not use § 2255 to attack those convictions. Id.
No. 17-1439                                                    23

       7. The Statutory Purpose Further Supports this Interpre-
          tation
    Finally, we consider the purpose of § 851(e). See Senne v.
Village of Palatine, 695 F.3d 597, 601 (7th Cir. 2012) (“Interpre-
tation of a word or phrase depends upon reading the whole
statutory text, considering the purpose and context of the stat-
ute[] … .” (alterations in original) (quoting Dolan, 546 U.S. at
486)).
    The purpose of § 851(e) is twofold. First, it prevents ad-
ministrative difficulties. By keeping collateral challenges to
old convictions out of the federal courts after a specified time,
§ 851(e) mitigates the “expense of keeping court records in-
definitely, concerns about evidence being lost over time, and
‘thorny procedural difficulties’ at sentencing hearings.”
McChristian, 47 F.3d at 1503 (quoting United States v. Davis, 36
F.3d 1424, 1438 (9th Cir. 1994)). The Daniels Court, interpreting
the ACCA, worried whether a district court would “have the
documents necessary to evaluate claims arising from long-
past proceedings in a different jurisdiction.” 532 U.S. at 379.
In Custis, the Court similarly expressed a concern that, if de-
fendants were allowed to attack a prior conviction during fed-
eral sentencing, this “would require sentencing courts to rum-
mage through frequently nonexistent or difficult to obtain
state-court transcripts or records that may date from another
era, and may come from any one of the 50 states.” 511 U.S. at
496. However, the Custis Court recognized an exception for
claims based on failure to appoint counsel, in part because the
basis for such claims “will generally appear from the judg-
ment roll itself, or from an accompanying minute order.” Id.
24                                                  No. 17-1439

    Second, § 851(e) protects the finality of state court judg-
ments. States “have a real and continuing interest in the integ-
rity of [their] judgments.” Daniels, 532 U.S. at 380. “By chal-
lenging the previous conviction, the defendant is asking a dis-
trict court to deprive the state-court judgment of its normal
force and effect in a proceeding that has an independent pur-
pose other than to overturn the prior judgment.” Custis, 511
U.S. at 497 (internal quotation marks and alterations omitted).
In the ACCA context, the Supreme Court was concerned that
such a collateral attack “would effectively permit challenges
far too stale to be brought in their own right, and sanction an
end run around statutes of limitations and other procedural
barriers that would preclude the movant from attacking the
prior conviction directly” in state court. Daniels, 532 U.S. at
383.
    Neither of those concerns are implicated where, as here,
the petitioner directly attacked the prior conviction in state
court and the state court vacated the prior conviction. The
government complains that the state court case files have been
archived or discarded and that, due to the passage of time,
victims may be unavailable or unwilling to testify. Critically,
though, Arreola-Castillo is not asking the district court to
rummage through old case files and hear from witnesses to
determine whether his prior convictions were invalid. The
New Mexico state court already adjudicated the matter and
vacated his prior convictions on that ground. Now, Arreola-
Castillo is simply asking the district court to look at the state
court’s orders to that effect. Like a claim based on failure to
appoint counsel, a claim based on vacatur of a prior state con-
viction will be apparent from the state court’s orders. Moreo-
ver, there is no concern about protecting the finality of state
court judgments because New Mexico already deprived its
No. 17-1439                                                    25

own judgments of force and effect by vacating them. In doing
so, the New Mexico state court clearly determined that Arre-
ola-Castillo’s claims did not run afoul of the state’s statutes of
limitations and procedural barriers.
                          III. Conclusion
    For the foregoing reasons, we REVERSE the judgment of the
district court.
