17 CFR 204.35: Petition for pre-offset hearing.

(a) The employee may petition for a pre-offset hearing. The petition must state with specificity why the employee believes the agency's determination is in error. To the extent that a debt has not been established by judicial or administrative order, a debtor may request a pre-offset hearing concerning the existence or amount of the debt or the terms of repayment. With respect to debts established by a judicial or administrative order, a debtor may request a pre-offset hearing concerning the payment or other discharge of the debt.

(b) The petition must fully identify and explain, with reasonable specificity, all the facts, evidence and witnesses, if any, that the employee believes support his or her position. The petition must be signed by the employee.