The Fifth Circuit held in United States v. Meredith that there is no right to appeal the sentencing court's determination of restitution where the plea agreement (1) includes a plea waiver, and (2) provides that the amount of restitution will be determined by the sentencing court, (3) without any specified limitation on the maximum amount of restitution that the court may impose. 

18 U.S.C. Section 3663(a)(3) provides that the "court may also order restitution in any criminal case to the extent agreed to by the parties in a plea agreement."  The plea agreement in this securities fraud cause apparently stated only that the sentencing court would determine the amount of restitution.  Because there was not any cap contained in the plea agreement, there was effectively no statutory maximum amount of restitution--and the trial court's imposition of $6.8 million in restitution was unreviewable on appeal.