It's the second appeal in the nine-year fraud investigation of former Philadelphia powerbroker Vincent Fumo.
Fumo is serving a 5-year sentence for defrauding the senate and two nonprofits.
Federal prosecutors believe the wealthy lawyer has the money to pay the $4.2 million restitution himself.
Fumo argues that he should pay $2.3 million, the original amount set by the trial judge before it was raised to $3.5 million on appeal.
Codefendant Ruth Arnao, a longtime Fumo aide, is paying about $750,000. But prosecutors say Fumo enjoyed 96 percent of the stolen goods and services.
In a federal appeals court Friday, Fumo lawyer Peter Goldenberger called the original restitution order fair and legal.
Fumo is scheduled for release in 2013.