MEMORANDUM **

Douglas Shields appeals from the 15-month sentence imposed following his guilty-plea conviction for conspiracy and aiding and assisting in the preparation of false tax returns, in violation of 18 U.S.C. § 371 and 26 U.S.C. § 7206. We have jurisdiction pursuant to 28 U.S.C. § 1291, and we affirm.

Shields contends that the district court failed to correctly calculate the total offense level, that the district court abused its discretion by failing to depart downward from his criminal history category, and that his sentence is unreasonable. We decline to address these contentions in light of the valid appeal waiver. See United States v. Nguyen, 235 F.3d 1179, 1182-83 (9th Cir. 2000).

AFFIRMED.