Affirmed by unpublished PER CURIAM opinion.

Unpublished opinions are not binding precedent in this circuit.

Douglas Mark Gilbert pleaded guilty, pursuant to a written plea agreement, to possessing child pornography, in violation of 18 U.S.C. § 2252A(a)(5)(B), (b)(2) (2012). On appeal, Gilbert challenges the district court’s imposition of a 15-year term of supervised release as substantively unreasonable. We affirm.

This court reviews a sentence’s reasonableness under “a deferential abuse-of-discretion standard.” Gall v. United States, 552 U.S. 38, 41, 128 S.Ct. 586, 169 L.Ed.2d 445 (2007). The sentence imposed must be “sufficient, but not greater than necessary,” to satisfy the purposes of sentencing. 18 U.S.C. § 3553(a) (2012). We apply a presumption of reasonableness on appeal to a within-Guidelines-range sentence. United States v. Helton, 782 F.3d 148, 151 (4th Cir. 2015) (affirming substantive reasonableness of lifetime term of supervised release in possession of child pornography appeal). “Such a presumption can only be rebutted by showing that the *196 sentence is unreasonable when measured against the § 3553(a) factors.” United States v. Louthian, 756 F.3d 295, 306 (4th Cir.) cert. denied — U.S. -, 135 S.Ct. 421, 190 L.Ed.2d 293 (2014).

After reviewing the record, we conclude that Gilbert’s sentence was substantively reasonable. His term of supervised release fell within his Guidelines range and was well below the lifetime term of supervised release advocated by the Government and probation office. The court weighed the seriousness of the offense, Gilbert’s criminal history, his need for substance abuse and sex offender treatment, and his age in assigning this term, and Gilbert has not rebutted its substantive reasonableness.

Accordingly, we affirm the district court’s judgment. We dispense with oral argument because the facts and legal contentions are adequately presented in the materials before this court and argument would not aid the decisional process.

AFFIRMED.