D was charged with four offenses: conspiracy to distribute crack and powder cocaine; possession with intent to distribute more than 50 grams of crack cocaine; possession with intent to distribute powder cocaine; and possession of a firearm in furtherance of a drug-trafficking offense. D pleaded guilty to all four charges. The District Court first calculated D’s sentence under the advisory Sentencing Guidelines. D’s final advisory Guidelines range was thus 228 to 270 months or 19 to 22.5 years. The District Court ruled that such a judgment would have been “greater than necessary” to accomplish the purposes of sentencing set forth in 18 U. S. C. §3553(a). As required by §3553(a), the court took into account the “nature and circumstances” of the offense and D’s “history and characteristics.” The court commented that the case exemplified the “disproportionate and unjust effect that crack cocaine guidelines have in sentencing.” If D had trafficked in powder cocaine, he would have had a range of 97 to 106 months, inclusive of the 5-year mandatory minimum for the firearm charge. The court sentenced Kimbrough to 15 years, or 180 months, in prison plus 5 years of supervised release. The Fourth Circuit vacated the sentence; a sentence “outside the guidelines range is per se unreasonable when it is based on a disagreement with the sentencing disparity for crack and powder cocaine offenses.” The Supreme Court granted certiorari.