Concepcion v. United States, 597 U.S. 481

Carlos Concepcion pleaded guilty in 2007 to distributing crack cocaine (≥5 g) and was sentenced in 2009 to 228 months; career-offender and other enhancements had raised his Guidelines range drastically.
Congress passed the Fair Sentencing Act (2010) to reduce the crack/powder disparity (raising the crack quantity thresholds) but did not make that change retroactive.
The Sentencing Commission issued a 2011 Guidelines amendment lowering crack ranges but it was not applicable to all prisoners (Concepcion was ineligible because of the career-offender status).
The First Step Act (2018) authorized district courts to “impose a reduced sentence” for certain pre‑2010 crack offenses “as if” the Fair Sentencing Act were in effect at the time of the offense.
Concepcion moved under the First Step Act; the Government conceded eligibility but opposed reduction based on (a) his original sentence already falling within the recalculated Guidelines and (b) disciplinary history. Concepcion argued additionally that post‑sentencing developments (vacatur of a prior conviction affecting career‑offender status and evidence of rehabilitation) warranted further reduction.
The district court declined to consider intervening changes of law or fact; the First Circuit affirmed (divided). The Supreme Court granted certiorari and reversed, holding that district courts may consider intervening changes of law or fact when exercising discretion under the First Step Act.

Issue	Concepcion's Argument	United States' Argument	Held
Whether district courts adjudicating First Step Act motions may consider intervening changes of law or fact (e.g., post‑sentencing rehabilitation, vacatur of prior convictions, nonretroactive Guidelines amendments) in deciding whether and how much to reduce a sentence	Yes — courts should be able to consider intervening legal/factual changes (career‑offender status change; rehabilitation) when exercising discretion to reduce a sentence	No — First Step Act confines courts to consider only the Fair Sentencing Act changes (calculate "as if" the Fair Sentencing Act applied) and not unrelated intervening changes	Yes — district courts may consider intervening changes of law or fact; they must consider parties’ nonfrivolous arguments and give a brief reasoned explanation but are not required to grant relief
What limits, if any, govern appellate review of a district court’s First Step Act decision	District court discretion should be reviewed deferentially; appellate courts should not substitute their judgment on sentencing adjustments	Appellate review should guard against inconsistent application and limit district courts’ importation of nonretroactive changes	Deferential review: appellate courts should not be overly searching except for legal errors in recalculating Guidelines per the Fair Sentencing Act

Dean v. United States, 581 U.S. 62 (2017) (recognizing judges’ broad discretion in the information they may consider at sentencing)
Koon v. United States, 518 U.S. 81 (1996) (sentencing judges should consider each defendant as an individual)
United States v. Tucker, 404 U.S. 443 (1972) (sentencing inquiry may be broad in scope and source of information)
Pepper v. United States, 562 U.S. 476 (2011) (district courts may consider evidence of post‑sentencing rehabilitation on resentencing)
Mistretta v. United States, 488 U.S. 361 (1989) (scope of judicial sentencing discretion subject to congressional limits)
Kimbrough v. United States, 552 U.S. 85 (2007) (Congress directs sentencing practices in express terms; district courts may consider Guidelines policy arguments)
Rita v. United States, 551 U.S. 338 (2007) (district courts need only provide a brief statement of reasons for sentencing decisions)
Gall v. United States, 552 U.S. 38 (2007) (standard for review of sentencing decisions)
Peugh v. United States, 569 U.S. 530 (2013) (Guidelines range serves as a benchmark for sentencing)
Solem v. Helm, 463 U.S. 277 (1983) (appellate courts should not substitute their judgment for sentencing courts')