MEMORANDUM **

Michael Gary Barber, a federal prisoner, appeals pro se the summary denial of his habeas corpus petition brought under 28 U.S.C. § 2241. He claims that under 18 U.S.C. § 3624(b) he is entitled to good-conduct sentence credit calculated on the basis of the length of his sentence, rather than the amount of time served. We have jurisdiction under 28 U.S.C. § 1291, and we affirm.

Barber contends that 28 C.F.R. § 523.20, the Federal Bureau of Prisons’ regulation interpreting § 3624(b) to mean *597that an inmate earns good-time credit on the basis of time served, contravenes the plain meaning of the statute and violates various other rules of statutory interpretation. This contention is foreclosed by Mujahid v. Daniels, 413 F.3d 991 (9th Cir. 2005), cert. denied, — U.S. —, 126 S.Ct. 2287, 164 L.Ed.2d 817 (2006), and Pacheco-Camacho v. Hood, 272 F.3d 1266 (9th Cir. 2001).

Barber contends that the regulation is not valid because it was not formally implemented via the Federal Register notice- and-comment procedure until 1997, and its application to him violates the Ex Post Facto Clause because he was convicted in 1993. This contention also is foreclosed by Pacheco-Camacho.

AFFIRMED.