ORDER AND JUDGMENT *

After the Sentencing Commission lowered the base offense levels for certain drug crimes, see U.S. Sentencing Guidelines Manual (U.S.S.G.) app. C, amend. 782 (Supp. 2014), federal prisoner Arnold Butler asked the district court to reduce his sentence under 18 U.S.C. § 3582(c)(2). But as the district court said in denying that request, Mr. Butler isn’t eligible for such a reduction because he’s a career offender whose sentence derives from a different and unchanged part of the sentencing guidelines. See U.S.S.G. § 4Bl.l(b). Mr. Butler appeals but he *518doesn’t address the basis for the district court’s decision and so has waived any challenge to it. United States v. Martinez, 518 F.3d 763, 767 n. 2 (10th Cir. 2008). Instead, he now voices an entirely different concern about his sentence, saying its imposition violated his constitutional rights under Apprendi v. New Jersey, 530 U.S. 466, 120 S.Ct. 2348, 147 L.Ed.2d 435 (2000) — an argument he failed to pursue in the district court and so cannot pursue here and one that must fail in any event for § 3582(c)(2) does not provide a vehicle for challenges of this sort. See United States v. Gay, 771 F.3d 681, 686 (10th Cir. 2014).

Affirmed.