“Controlled Substance” in U.S.S.G. § 4B1.2(b) Means CSA-Only: Massachusetts “Cocaine” Convictions Not Predicates if They Cover Ioflupane

I. Introduction

In United States v. Rosado Maldonado (1st Cir. July 6, 2026), the First Circuit vacated a felon-in-possession sentence after concluding that the district court miscalculated the defendant’s Guidelines range by treating two Massachusetts “cocaine” convictions as “controlled substance offense” predicates under U.S.S.G. § 2K2.1(a)(2), via the definition in U.S.S.G. § 4B1.2(b).

The central issue was interpretive and categorical: whether “controlled substance” in the Guidelines refers to substances controlled by either state or federal law (as the district court held), or only those controlled by the federal Controlled Substances Act (CSA) (as the defendant argued). The dispute mattered because Massachusetts’s definition of “cocaine” includes [123I]ioflupane (“ioflupane”), while federal law removed ioflupane from the CSA schedules in 2015. If “controlled substance” is CSA-only, the Massachusetts statutes are overbroad and fail the categorical match required for the enhancement.

The parties were the United States (appellee) and Joan Rosado Maldonado (defendant-appellant), who pleaded guilty to violating 18 U.S.C. § 922(g)(1).

II. Summary of the Opinion

The First Circuit held that, for Guidelines purposes, the term “controlled substance” (as used in the definition of “controlled substance offense” in U.S.S.G. § 4B1.2(b)) encompasses only substances regulated by the federal CSA, not substances controlled solely under state law. Applying that rule, the court concluded that Massachusetts “cocaine” offenses are not categorical matches to the CSA when the state definition includes ioflupane but the CSA does not.

Because the district court used the two Massachusetts convictions (2010 cocaine trafficking; 2019 possession with intent to distribute a Class B substance) to set a base offense level of 24 under § 2K2.1(a)(2), the Guidelines range was procedurally miscalculated. The court found no basis to deem the error harmless and therefore vacated the sentence and remanded for resentencing.

The panel did not reach challenges to supervised-release conditions (including discrepancies between oral and written pronouncements), noting that resentencing would allow the district court to clarify any ambiguity.

III. Analysis

A. Precedents Cited

  • United States v. Santa-Soler, 985 F.3d 93, 95 (1st Cir. 2021)
    Cited for the record basis in guilty-plea cases: the court draws facts from the plea colloquy, unchallenged PSR portions, and the sentencing transcript. This framed how the panel treated the factual backdrop without expanding into contested factual disputes.
  • United States v. Berroa, 856 F.3d 141, 162 (1st Cir. 2017)
    Cited for the standard of review: Guidelines interpretation is reviewed de novo. That mattered because the principal issue was legal—what “controlled substance” means in the Guidelines—not discretionary factfinding.
  • United States v. Fulcar, No. 25-1524, slip op. at 33-45 (1st Cir. July 6, 2026)
    The opinion’s engine. Fulcar resolved the interpretive question and supplied the reasoning the panel adopted here: “controlled substance” in the Guidelines is limited to CSA-controlled substances. The panel also noted Fulcar’s timing rule (slip op. at 32): the relevant comparison point is the CSA schedules at the time of federal sentencing.
  • United States v. Crocco, 15 F.4th 20, 21 (1st Cir. 2021)
    Cited to confirm application of the categorical approach where neither party argues for the modified categorical approach. Here, the government did not contest that categorical analysis governed.
  • United States v. Rosa-Borges, 174 F.4th 281, 290 (1st Cir. 2026)
    Cited for harmless-error principles in Guidelines miscalculation cases: vacatur is required unless the reviewing court is convinced the district court “inevitably” would have imposed the same sentence absent the error. The district judge’s statement—she could not “say what [she] would have done if the PSR was different”—made harmlessness untenable.
  • United States v. Diaz, 285 F.3d 92, 98 (1st Cir. 2002)
    Quoted via Rosa-Borges for the “inevitably” standard governing whether a Guidelines error can be treated as harmless.

B. Legal Reasoning

1. The enhancement framework.
Under U.S.S.G. § 2K2.1(a)(2), a firearm defendant’s base offense level is 24 if he committed the federal firearm offense after sustaining at least two felony convictions for a “controlled substance offense.” The commentary to § 2K2.1 incorporates the definition in U.S.S.G. § 4B1.2(b).

2. The meaning of “controlled substance.”
The district court read “controlled substance” to include drugs controlled under state law, even if not controlled under the CSA. The First Circuit rejected that reading, adopting United States v. Fulcar’s conclusion that “controlled substance” in this Guidelines context is CSA-only. As a result, whether a state conviction qualifies depends on whether the state statute covers no more conduct/substances than the CSA definition at the relevant time.

3. The categorical mismatch (ioflupane overbreadth).
Massachusetts schedules ioflupane as a Class B substance as part of its “cocaine” definition, while federal law removed ioflupane from Schedule II in 2015. Because ioflupane remained within the Massachusetts definition at the time of Maldonado’s federal sentencing, the Massachusetts “cocaine” offenses sweep more broadly than CSA-controlled substances. Under the categorical approach, that overbreadth means the convictions are not “controlled substance offense” predicates for § 2K2.1(a)(2).

4. Timing.
The panel flagged that Fulcar uses the time of federal sentencing as the benchmark for determining whether the state definition matches the CSA schedules. That matters in ioflupane cases because federal scheduling changed in 2015: the same state conviction can qualify or not qualify depending on the federal sentencing date.

5. Remedy (procedural error and harmlessness).
A Guidelines range miscalculation is a procedural sentencing error. Applying United States v. Rosa-Borges, the panel vacated because the record did not show the district court would have imposed the same sentence regardless—indeed, the judge expressly stated she could not say what she would have done with a different PSR/Guidelines calculation.

6. Supervised release conditions left for resentencing.
Although the opinion recounts potential discrepancies between oral and written supervised-release conditions (gang association, association with persons engaged in criminal activity, and firearm-related associational restrictions), the court declined to resolve them because resentencing would allow the district court to clarify and reimpose conditions cleanly.

C. Impact

1. Narrowing predicate drug convictions for Guidelines enhancements.
By adopting a CSA-only definition of “controlled substance,” the decision (via Fulcar) narrows when state drug convictions can trigger higher base offense levels under § 2K2.1(a)(2) and, by implication, other Guideline provisions incorporating § 4B1.2(b). State schedules that include substances not controlled federally (or define drugs more broadly) will fail the categorical match and cannot serve as predicates.

2. Special significance for Massachusetts “cocaine” statutes.
The ioflupane mismatch creates a recurring litigation pathway: defendants with Massachusetts “cocaine” convictions may avoid enhanced base offense levels if sentenced federally after ioflupane’s federal descheduling, so long as the Massachusetts definition still includes it and the categorical approach applies.

3. Sentencing practice effects.
Probation offices, prosecutors, and defense counsel must audit predicate convictions against the CSA schedules at the time of federal sentencing, not merely assume state drug convictions are interchangeable with federal controlled substances. District courts should expect more contested PSR objections and more careful predicate analyses.

4. Supervised release drafting discipline.
While not decided, the opinion’s discussion underscores a practical warning: inconsistencies between oral pronouncements and written judgments (and ambiguously broad association restrictions, including firearm-related “be found with” language) invite appeal and remand risk—especially where resentencing is required anyway.

IV. Complex Concepts Simplified

“Controlled substance offense” (Guidelines)
A defined category of prior convictions (federal or state) that can increase a defendant’s Guidelines range. Here, the key question was what substances count as “controlled.”
CSA-only rule
The court’s rule that “controlled substance” in the Guidelines means substances controlled under the federal Controlled Substances Act—so a state’s broader list does not expand what counts for the federal enhancement.
Categorical approach
A method that compares the elements of the state offense (including the substances it reaches) to the federal definition. If the state statute covers more conduct/substances than the federal definition, the conviction does not qualify—regardless of what the defendant actually possessed in his case.
Ioflupane
A cocaine-derived substance. Massachusetts treats it within its “cocaine” scheduling, but federal law removed it from the CSA schedules in 2015—creating the overbreadth that defeats the categorical match.
Harmless error in Guidelines calculation
Even if a mistake occurred, an appellate court may affirm if it is clear the same sentence would have been imposed anyway. Here, that clarity was absent (and the judge’s comments pointed the other way), so resentencing was required.

V. Conclusion

United States v. Rosado Maldonado applies the First Circuit’s same-day holding in United States v. Fulcar to vacate a firearm sentence inflated by treating Massachusetts “cocaine” convictions as “controlled substance offense” predicates. The opinion’s core significance is its firm adoption of a CSA-only meaning of “controlled substance” in U.S.S.G. § 4B1.2(b), combined with categorical analysis that treats Massachusetts’s inclusion of ioflupane as dispositive overbreadth when federal law does not control that substance at the time of federal sentencing. The decision is poised to reshape predicate-drug litigation in the First Circuit wherever state drug definitions extend beyond the CSA.