In May 2006, Herminio Cortorreal, pro se, filed in the District Court a motion for resentencing in which he argued that he was entitled to resentencing under 18 U.S.C. § 3582(c)(2), and the Supreme Court’s decision in United States v. Booker, 543 U.S. 220, 125 S.Ct. 738, 160 L.Ed.2d 621 (2005). Specifically, Cortor-real argued that, because Booker had constituted both an implicit lowering of the United States Sentencing Guidelines (“Guidelines”) and a new rule of law that was retroactive to cases on collateral review, he was entitled to a new sentence. In July 2006, the District Court issued an order denying the motion, finding, inter alia, that (1) because the United States Sentencing Commission had not lowered the Guidelines range applicable to Cortor-real’s case, he was not entitled to resen-tencing under Section 3582(c)(2); and (2) Booker did not apply retroactively to Cor-torreal’s case. Thereafter, Cortorreal filed a timely notice of appeal from the District Court decision. Cortorreal now moves this Court for leave to proceed in forma pauperis.
As a preliminary matter, review of the District Court docket sheet indicates that Cortorreal received counsel pursuant to the Criminal Justice Act, which would have required him to receive in forma pauperis status in the District Court. There is no indication that the District Court revoked Cortorreal’s in forma pauperis status at any time during the proceedings. Accordingly, Cortorreal’s motion for leave to proceed in forma pauperis is denied as unnecessary.
Further, independent of the in for-ma pauperis motion, this Court must dismiss Cortorreal’s appeal if it is frivolous. See 28 U.S.C. § 1915(e)(2)(B)®. An appeal is frivolous “where it lacks an arguable basis either in law or in fact.” Neitzke v. Williams, 490 U.S. 319, 325, 109 S.Ct. 1827, 104 L.Ed.2d 338 (1989).
We have not previously determined the appropriate standard of review to apply to a district court decision denying a motion under Section 3582(c)(2). Those circuits that have addressed the issue have determined that such a decision should be reviewed for abuse of discretion. See, e.g., United States v. Rodriguez-Pena, 470 F.3d 431, 432 (1st Cir.2006) (per curiam); United States v. Moreno, 421 F.3d 1217, 1219 (11th Cir.2005) (per curiam). We need not decide the standard of review here, however, because Cortorreal’s appeal lacks merit under any standard of review, even in light of the arguments raised in his response to the Government’s opposition, because the District Court properly determined that Cortorreal did not merit resen-tencing under either Section 3582(c)(2) or Booker. Accordingly, we find that Cortor-real’s appeal is frivolous.
*744A district court may not generally modify a term of imprisonment once it has been imposed. See United States v. Thomas, 135 F.3d 873, 876 (2d Cir.1998) (“Congress has imposed stringent limitations on the authority of courts to modify sentences, and courts must abide by those strict confines.”). However, under 18 U.S.C. § 3582(c)(2), a court may reduce the term of imprisonment of a “defendant who has been sentenced to a term of imprisonment based on a sentencing range that has subsequently been lowered by the Sentencing Commission pursuant to 28 U.S.C. § 994(o).” Section 994(o) requires the Sentencing Commission to “periodically ... review and revise ... the guidelines promulgated pursuant to” the duties of the Sentencing Commission.
Cortorreal argues that, because Booker rendered the Guidelines advisory, it implicitly lowered the sentencing range applicable to his case, and, thus, constituted sufficient reason for relief under Section 3582(c)(2). We have not yet addressed whether the decision in Booker can serve as the basis for a motion to reduce a sentence pursuant to Section 3582(c)(2). However, those courts that have addressed the issue have determined that, although Booker affected the application of the Guidelines, because the decision was not a guideline amendment promulgated by the Sentencing Commission, the terms of Section 3582(c)(2) did not apply. See, e.g., United States v. Price, 438 F.3d 1005, 1007 (10th Cir.2006); United States v. Moreno, 421 F.3d 1217, 1220 (11th Cir.2005) (“Booker is a Supreme Court decision, not a retroactively applicable guideline amendment by the Sentencing Commission. Therefore, Booker is inapplicable to § 3582(c)(2) motions.”). We follow our sister circuits in holding that, because Booker was not a guideline amendment promulgated by the Sentencing Commission, the terms of Section 3582(c)(2) do not apply, and therefore the Booker decision cannot be the basis for a Section 3582(c)(2) motion to modify a sentence. Accordingly, the District Court properly denied Cortor-real’s motion to the extent that it sought a reduction in his sentence pursuant to Section 3582(c)(2).
Finally, to the extent that Cortorreal sought retroactive application of Booker to his case, the District Court also properly denied the motion. We have previously determined that Booker does not apply retroactively to cases, such as this one, on collateral review. See Guzman v. United States, 404 F.3d 139, 140 (2d Cir.2005).
For the foregoing reasons, Cortorreal’s motion to proceed in forma pauperis is Denied and his appeal is Dismissed pursuant to 28 U.S.C. § 1915(e)(2)(B)(i).