Petitioner, Elvis Martinez, was convicted of two state drug offenses for distribution of a small quantity of marihuana.2 The question before us is whether, under Lopez v. Gonzales, 549 U.S. 47, 127 S.Ct. 625, 166 L.Ed.2d 462 (2006), these state convictions are “aggravated felonies” under the INA. To determine whether the state convictions count as aggravated felonies, we must decide whether they are the equivalent of federal felony drug trafficking, under the Controlled Substances Act (CSA), see 21 U.S.C. §§ 841(a)(1), (b)(1)(D), or rather are the equivalent of a federal misdemeanor in light of the CSA’s mitigating exception that punishes distribution of “a small amount of marihuana for no remuneration” as a misdemeanor, see 21 U.S.C. § 841(b)(4). Because the state conviction could have been for nonremunerative transfer of as little as two grams of marihuana, we hold that under our categorical approach, Petitioner’s conviction is the equivalent of a federal misdemeanor under the CSA and not an aggravated felony.
*116I. Factual and Procedural Background
A. Prior Criminal Convictions
Elvis Martinez is a 27-year-old native of the Dominican Republic. He has been a lawful permanent resident of the United States since 1989. On March 3, 2000, Martinez was convicted following a guilty plea of criminal sale of marihuana in the fourth degree, a misdemeanor, in violation of N.Y. Penal Law § 221.40. On April 18, 2001, he again pled guilty and was convicted of the same offense.
B. Initial Round of Removal Proceedings
The Government began removal proceedings against Martinez by serving him with a Notice to Appear on June 21, 2001. The Government initially charged two grounds of removability based solely on the March 2000 conviction. The first was for conviction of a controlled substance violation, pursuant to INA § 237(a)(2)(B)(I), 8 U.S.C. § 1227(a)(2)(B)(I). The second ground was for conviction of an aggravated felony, as defined in INA § 101(a)(43)(B), pursuant to INA § 237(a)(2)(A)(iii), 8 U.S.C. § 1227(a)(2) (A) (iii).
A hearing was held before an Immigration Judge (IJ) on September 24, 2003. Martinez admitted committing a controlled substance violation but denied that he had been convicted of an aggravated felony. He, therefore, conceded removability under INA § 237(a) (2) (B) (i), but sought cancellation of removal, for which he was eligible so long as he was not found to have committed an aggravated felony.
At the same hearing, Martinez relied on a Third Circuit case, Steele v. Blackman, 236 F.3d 130, 131 (3d Cir.2001), which held that a conviction under New York Penal Law § 221.40 did not constitute an aggravated felony. Martinez further argued that our decision in United States v. Simpson, 319 F.3d 81 (2d Cir.2002), which seemingly cut against him, was limited to the sentencing context only and did not cover removability.
After considering whether Martinez had been convicted of an aggravated felony within the meaning of the INA, the IJ ruled on October 24, 2003 that Martinez’s drug convictions were aggravated felonies, thereby precluding his eligibility for cancellation of removal under INA § 240A(a)(3). The IJ characterized the question as “troubling.” He said that the BIA had held in In re Elgendi, 23 I. & N. Dec. 515 (BIA 2002), that a state drug offense was only an aggravated felony if it was a felony in the state in which it was committed, but that the Second Circuit had held in Aguirre v. INS, 79 F.3d 315 (2d Cir.1996), and Simpson, 319 F.3d at 85, that a state drug offense was an aggravated felony if it would be a felony under federal law. Declaring himself bound by the Second Circuit, the IJ held that Martinez’s convictions were aggravated felonies. The BIA summarily affirmed.
Martinez filed a habeas petition in the Eastern District of New York on April 15, 2004. It was transferred to the Western District of New York and then, after full briefing to the district court, transferred to the Second Circuit on June 20, 2005, pursuant to the REAL ID Act.
The case was argued before our court on May 18, 2006. The panel initially waited to make a decision until the Supreme Court had ruled in Lopez v. Gonzales, 549 U.S. 47, 127 S.Ct. 625, 166 L.Ed.2d 462 (2006). After the Supreme Court decided Lopez, we requested supplemental briefing on the impact of that decision. On May 8, 2007, we remanded the case to the BIA for reconsideration in light of Lopez.
*117C. Remand to the BIA
On remand, the BIA did not request briefing. Rather, the Board simply rendered a new decision ordering that Martinez should be removed as an aggravated felon who is thus ineligible for relief. The Board observed that under Lopez, the question of whether Martinez’s state conviction was an aggravated felony under the INA rested upon whether that crime would have been punishable as a felony under the CSA, 21 U.S.C. § 801 et. seq. The Board reasoned that the New York crime of sale of marihuana is comparable to the federal crime of marihuana distribution, 21 U.S.C. § 841(a)(1), which pursuant to 21 U.S.C. § 841(b)(1)(D), is punishable by up to five years in prison and is therefore a felony.
In so doing, the BIA held that although the distribution of “a small amount of marihuana for no remuneration” is punished as a misdemeanor under 21 U.S.C. § 841(b)(4), that misdemeanor provision is a mitigating exception in a sentencing statute in which a federal defendant bears the burden of showing that he falls into the lower misdemeanor category. The Board held, therefore, (a) that Martinez bore the burden of showing that his state crime was the equivalent of a federal misdemeanor and (b) that he had not met this burden.
II. Discussion
A. Standard of Review
Whether a conviction qualifies as an aggravated felony is a question of law, Dulal-Whiteway v. DHS, 501 F.3d 116, 120 (2d Cir.2007), which we review de novo, 8 U.S.C. § 1252(a)(2)(D).
B. Legal Framework
A permanent resident alien is eligible to apply for cancellation of removal if the alien “(1) has been an alien lawfully admitted for permanent residence for not less than 5 years, (2) has resided in the United States continuously for 7 years after having been admitted in any status, and (3) has not been convicted of any aggravated felony.” 8 U.S.C. § 1229b(a). Only the third of these conditions is in dispute in this case.
In pertinent part, the INA defines the term “aggravated felony” to include “illicit trafficking in a controlled substance (as defined in Section 102 of the Controlled Substances Act) including a drug trafficking crime (as defined in section 924(c) of title 18, United States Code).” INA § 101(a)(43)(B), as added by § 7342, 102 Stat. 4469, and as amended by § 222(a), 108 Stat. 4320, 8 U.S.C. § 1101(a)(43)(B), 8 U.S.C. § 1101(a)(43). Under the CSA, a “controlled substance” is “a drug or other substance, or immediate precursor, included in schedule I, II, III, IV, or V of part B of [21 U.S.C. § 812].” 21 U.S.C. § 802(6). Marihuana is a schedule I drug under the CSA. 21 U.S.C. § 812.
The general phrase “illicit trafficking” is left undefined, but 18 U.S.C. § 924(c)(2) identifies the subcategory by stating that a “drug trafficking crime” is “any felony punishable under the Controlled Substances Act” (or under either of two other federal statutes having no bearing on this case). Following the listing, § 101(a)(43) of the INA provides in its penultimate sentence that “[t]he term [aggravated felony] applies to an offense described in this paragraph whether in violation of Federal or State law” (or, in certain circumstances, “the law of a foreign country.”). 8 U.S.C. § 1101(a)(43). The United States Supreme Court has held that “a state offense constitutes a ‘felony punishable under the Controlled Substances Act’ only if it proscribes conduct punishable as a felony under that federal law.” Lopez, 127 S.Ct. at 633. Thus, for a state drug *118offense to qualify as a “drug trafficking crime” and, by extension, an aggravated felony, it must correspond to an offense that carries a maximum term of imprisonment exceeding one year under the CSA. See id. at 631 & n. 7.
In deciding whether a conviction fits within the definition of “aggravated felony” in 8 U.S.C. § 1101(a)(43), we have followed the Supreme Court in adopting a “categorical approach.” Gertsenshteyn v. Mukasey, 544 F.3d 137, 143 (2d Cir.2008). Under this approach, which is sometimes called the Taylor-Shepard approach, after Taylor v. United States, 495 U.S. 575, 110 S.Ct. 2143, 109 L.Ed.2d 607 (1990), and Shepard v. United States, 544 U.S. 13, 125 S.Ct. 1254, 161 L.Ed.2d 205 (2005), “ ‘the singular circumstances of an individual petitioner’s crimes should not be considered, and only the minimum criminal conduct necessary to sustain a conviction under a given statute is relevant]!]’ ” Gertsenshteyn, 544 F.3d at 143 (quoting Dalton v. Ashcroft, 257 F.3d 200, 204 (2d Cir.2001)) (alteration in original).3 We thus “ ‘look to the elements and the nature of the offense of conviction, rather than to the particular facts relating to petitioner’s crime.’ ” Dulal-Whiteway, 501 F.3d at 121 (quoting Canada v. Gonzales, 448 F.3d 560, 565 (2d Cir.2006)).4
The outcome of such a categorical inquiry, moreover, may be different when defining aggravated felonies in the immigration context than in the sentencing context. This is the result of our bifurcated approach to defining aggravated felonies. See United States v. Pornes-Garcia, 171 F.3d 142 (2d Cir.1999); Aguirre v. INS, 79 F.3d 315 (2d Cir.1996). In Pomes-Garcia, we considered the “narrow issue” of “whether this Court’s construction of the phrase ‘aggravated felony’ in a deportation statute applies to the same phrase used in the Sentencing Guidelines for purposes of determining a sentencing enhancement for an immigration offense.” 171 F.3d at 143. We held that it does not. See id. at 143-45. Therefore, to the extent that we must define an aggravated felony, that definition need not comport with the definition used outside of the immigration context.5
*119C. Analysis
Martinez argues chiefly that the BIA erred in placing the burden on him to show that his New York State conviction did not fall within the federal misdemeanor provision, 21 U.S.C. § 841(b)(4), and in finding that his New York State conviction was the equivalent of a federal felony under 21 U.S.C. §§ 841(a)(1), (b)(1)(D), rather than a federal misdemeanor under 21 U.S.C. § 841(b)(4).
New York Penal Law § 221.40, criminal sale of marihuana in the fourth degree, covers distribution of very small quantities of marihuana. One is “guilty of criminal sale of marihuana in the fourth degree when he knowingly and unlawfully sells marihuana except as provided in section 221.35 of this article.” N.Y. Penal Law § 221.40. Section 221.35 punishes sale of two grams or less or a single marihuana cigarette for no consideration. Section 221.40, therefore, covers sale of over two grams of marihuana.6 While section 221.40 covers criminal “sale,” the definition of “sale” under New York law is a broad one that includes “any form of transfer of a controlled substance,” whether or not the transfer was for money. People v. Starling, 85 N.Y.2d 509, 626 N.Y.S.2d 729, 650 N.E.2d 387, 390 (1995).
Federal law makes it a felony for any person “knowingly or intentionally to manufacture, distribute, or dispense, or possess with intent to distribute, or dispense, [marihuana].” 21 U.S.C. § 841(a)(1). The lowest level federal offense, which involves a maximum sentence of five years’ imprisonment, applies, with an important exception, to anyone whose marihuana quantity is less than 50 kilograms. 21 U.S.C. § 841(b)(1)(D).7 The exception, 21 U.S.C. § 841(b)(4), states that “[Notwithstanding [21 U.S.C. § 841(b)(1)(D) ], any person who ... distribute[s] a small amount of marihuana for no remuneration shall be treated as provided in” 21 U.S.C. § 844, penalty for simple possession as misdemeanor. 21 U.S.C. § 841(b)(4) is not just *120a stand-alone subsection but is also referenced directly in 21 U.S.C. § 841(b)(1)(D), which states that for eases of less than 50 kilograms of marihuana, “except as provided in paragraphs (4) and (5) of this subsection,” the maximum sentence is five years. We have stated that the activity covered by 21 U.S.C. § 841(b)(4) is not merely “one of lesser degree than those covered by (b)(1)(D) but of a different type more akin to simple possession than to provisions intended to cover traffickers.” United States v. Outen, 286 F.3d 622, 637 (2d Cir.2002).8
Under the categorical approach, the Supreme Court has instructed us to look at the necessary elements of Martinez’s state conviction and then determine whether those elements, if prosecuted pursuant to federal criminal law, would necessarily be punishable as a felony. See Lopez, 127 S.Ct. at 630, 633; see also Dalton, 257 F.3d at 204. Martinez’s New York conviction could have been for any form of nonremunerative transfer of as little as two grams of marihuana. See N.Y. Penal Law § 221.40; Starling, 626 N.Y.S.2d 729, 650 N.E.2d at 390. Although the precise bounds of 21 U.S.C. § 841(b)(4) are not well defined, the minimum conduct of which Martinez might have been convicted is of “a different type more akin to simple possession than to provisions intended to cover traffickers.” Outen, 286 F.3d at 637.9 As the categorical approach requires, we look no further than to the fact that Martinez’s conviction could have been for precisely the sort of nonremunerative transfer of small quantities of marihuana that is only a federal misdemeanor under 21 U.S.C. § 841(b)(4).
The Government first attempts to avoid this straightforward application of the categorical approach by arguing that the question of law currently before us was already decided in United States v. *121 Simpson, 319 F.3d 81. That is simply not the case. Simpson was a sentencing enhancement case that construed “aggravated felony” under U.S.S.G. § 2L1.2(b), as applied to three convictions under N.Y. Penal Law § 221.40 (the same statute at issue in the present case). Simpson held that the convictions were “punishable under federal law” as felonies, and therefore were aggravated felonies “for purposes of sentencing under the Guidelines.” Id. at 85. The panel attached a footnote to the relevant passage saying, “We offer no comment on whether such convictions constitute ‘aggravated felonies’ for any purpose other than the Guidelines.” Id. at 86 n. 7.
Simpson does not in any way dictate the answer to the question of law now before us. It is quite self-consciously only the law of the circuit for cases under the Sentencing Guidelines. See id. at 86 n. 7. Moreover, because Simpson in no way could — or sought to — overrule the use of the bifurcated approach, see United States v. Wilkerson, 361 F.3d 717, 732 (2d Cir. 2004), even without its stated limitation to the sentencing context, it would not define an aggravated felony under the INA.10
The Government further attempts to avoid a straightforward application of the categorical approach by arguing that it was Martinez s burden to prove that his state conviction would be punishable under 21 U.S.C. § 841(b)(4), and hence not be an aggravated felony. This argument is unavailing. The very basis of the categorical approach is that the sole ground for determining whether an immigrant was convicted of an aggravated felony is the minimum criminal conduct necessary to sustain a conviction under a given statute. Dalton, 257 F.3d at 204. This does not require Martinez to prove how little marihuana he had or the nature of the transfer, so long as his conviction could have been based on a nonremunerative transfer of a small amount of marihuana. Placing the burden on Martinez, instead, necessarily requires looking into evidence of Martinez’s actual conduct, evidence that may never have been seen by the initial convicting court. It was the desire to avoid such particular inquiries — whether designed to show that a specific defendant was less or more culpable than what his actual conviction required — that led us and the Supreme Court to focus on categorical analysis.
Nor does the categorical approach leave room for the BIA to enter into the sort of fact finding that would be required if the burden were on aliens to prove that their state conviction falls into the federal *122misdemeanor exception, 21 U.S.C. § 841(b)(4). “The Taylor and Shepard Courts were also concerned with the practical implications of requiring a district court to take and weigh extraneous evidence, both in terms of fairness to the defendant and burden on the court.” Gertsenshteyn, 544 F.3d at 143. For “the BIA and reviewing courts are ill-suited to readjudicate the basis of prior criminal convictions.” Dulah-Whiteway, 501 F.3d at 132.11 In short, were Martinez to bear the burden, the BIA would be required to look to “the particular facts relating to petitioner’s crime” to determine if the petitioner committed an “aggravated felony,” and that is precisely what we have instructed the agency not to do. See id. at 121 (internal quotation marks and citations omitted).
The Government makes one additional and rather startling argument. It contends that because under 8 U.S.C. § 1228(c)(4), Martinez bears the burden of proving that he is eligible for cancellation relief, he has to show not only that he has not committed an aggravated felony, but also that the particular conduct which led to his conviction in state court would not qualify as a federal felony. This argument flies in the face of the categorical approach insofar as it requires any alien seeking cancellation of removal to prove the facts of his crime to the BIA. Although an alien must show that he has not been convicted of an aggravated felony, he can do so merely by showing that he has not been convicted of such a crime. And, as we have discussed supra, under the categorical approach, a showing that the minimum conduct for which he was convicted was not an aggravated felony suffices to do this.
We conclude that the BIA erred by placing the burden on Martinez to show that his conduct was the equivalent of a federal misdemeanor. We further hold that his conviction for violation of N.Y. Penal Law § 221.40 establishes nothing more than a crime punishable under 21 U.S.C. § 841(b)(4). We therefore VACATE the BIA’s decision and REMAND for further consideration consistent with this opinion.