Juan Alamo-Santellanes directly appeals the sentence imposed by the district court 1 after he pleaded guilty to a drug offense. His counsel has moved to withdraw, and has filed a brief under Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967), arguing that Alamo-Santellanes’s statutory-minimum prison term is substantively unreasonable.

After careful review, we conclude that Alamo-Santellanes’s challenge to his sentence fails because the district court lacked authority to impose a sentence below the statutory minimum. See United States v. Watts, 553 F.3d 603, 604 (8th Cir. 2009) (per curiam) (district courts lack authority to reduce sentences below congressionally-mandated statutory mínimums); United States v. Gregg, 451 F.3d 930, 937 (8th Cir. 2006) (United States v. Booker, 543 U.S. 220, 125 S.Ct. 738, 160 L.Ed.2d 621 (2005), does not relate to statutorily imposed sentences). Having reviewed the record independently in accordance with Benson v. Ohio, 488 U.S. 75, 80, 109 S.Ct. 346, 102 L.Ed.2d 300 (1988), we find no nonfrivolous issues. Therefore, we grant counsel’s motion to withdraw, subject to counsel informing Alamo-Santellanes about procedures for seeking rehearing or filing a petition for certiorari. The judgment is affirmed.