Byron Keith Thomas, a federal prisoner convicted of two crack cocaine offenses and a firearm offense, appeals the denial of his 18 U.S.C. § 3582(c)(2) motion for a sentence reduction. After review, we affirm. 1

Under § 3582(c)(2), a district court has the authority to modify a defendant’s term *753 of imprisonment if the defendant’s sentence was “based on a sentencing range that has subsequently been lowered by the Sentencing Commission pursuant to 28 U.S.C. [§ ] 994(o).” 18 U.S.C. § 3582(c)(2); see also U.S.S'.G. § lB1.10(a)(l). However, if the retroactively applicable amehdment to the guidelines “reduee[d] a defendant’s base offense level, but does not alter the sentencing range upon which his or her sentence was based, § 3582(c)(2) does not authorize a reduction in sentence.” United States v. Moore, 541 F.3d 1323, 1330 (11th Cir. 2008); see also U.S.S.G. § lB1.10(a)(2)(B).

A sentence reduction is not authorized if the amendment does not lower a defendant’s applicable guidelines range “because of the operation of another guideline or statutory provision.” U.S.S.G. § 1B1.10 cmt. n.l(A). Thus, when defendant’s applicable guidelines range is determined by his status as an armed career criminal, pursuant to U.S.S.G. § 4B1.4, and not by the amount of crack cocaine involved in his offense, pursuant to U.S.S.G. § 2Dl.l(c), the defendant is not eligible for §' 3582(c)(2) relief based on recent amendments to the base offense levels in § 2Dl.l(c) for crack cocaine offenses. See, e.g., United States v. Thomas, 545 F.3d 1300, 1301-02 (11th Cir. 2008) (involving § 3582(c)(2) motion based on Amendment 706).

Here, the district court did not err in denying Thomas’s § 3582(c)(2) motion. Thomas’s motion was based on Amendment 750, which changed the drug quantity tables in U.S.S.G. § 2Dl.l(c) to conform to the Fair Sentencing Act of 2010. See U.S.S.G. app. C, amends. 750, 759 (making Amendment 750 retroactive); U.S.S.G. § lB1.10(c) (listing Amendment 750 as an amendment for which a defendant may file a § 3582(c)(2) motion). Because Thomas was designated an armed career criminal at his original sentencing, his offense level was based on U.S.S.G. § 4B1.4, not on the drug quantity tables in U.S.S.G. § 2Dl.l(c). See Thomas, 545 F.3d at 1301. 2 Thus, Amendment 750 had no effect on Thomas’s ultimate sentencing range.

We find no merit to Thomas’s argument that he is eligible for § 3582(c)(2) relief because U.S.S.G. § 4B1.4’s armed career criminal enhancement applied only to his firearm conviction (Count 1) and not to his two crack cocaine convictions (Counts 2 and 3). At sentencing, the district court grouped all three counts for purposes of calculating Thomas’s offense level, pursuant to U.S.S.G. § 3D1.2(c). The court then determined that the applicable offense level was 34, pursuant to U.S.S.G. § 4B 1.4(b)(3)(A). Thus, Thomas’s offense level for all three counts was based on § 4B1.4(b)(3)(A), which was not changed by Amendment 750.

For these reasons, the district court correctly concluded that Thomas was ineligible for a § 3582(c)(2) sentence reduction.

AFFIRMED.