29 C.F.R. § 1650.112
Unless a debt is paid in full within 30 days of receipt of the Notice of Debt, the Commission will charge interest at the rate established in accordance with 31 U.S.C. 3717 effective on the date of delinquency, and a processing charge pursuant to 31 U.S.C. 3717 . The Commission will charge a penalty, pursuant to 31 U.S.C. 3717(e)(2) not to exceed 6 percent a year, on the amount due on a debt that is delinquent more than 90 days. This charge shall accrue from the date of delinquency. If an employee files a timely proposal for a repayment agreement, request for waiver, or a request for a hearing, interest, penalties, and administrative costs will be suspended during the time the Commission is considering such request(s).
29 C.F.R. § 1650.112