41 C.F.R. § 105-56.010 – Deductions.

(a) When deductions may begin. Deductions may begin upon the issuance of an Agency decision on a request for reconsideration or waiver (except as provided in § 105-56.005(b) of this subpart) or the issuance of a decision in a pre-offset hearing. In no event will deductions begin sooner than thirty days from the date of the notice letter. If the employee filed a petition for hearing with the appropriate program official before the expiration of the period provided for in § 105-56.006 of this subpart, then deductions will begin after the hearing official has provided the employee with a hearing and the final written decision. The appropriate program official will coordinate with the National Payroll Center to begin offset in accordance with the final written decision.
(b) Retired or separated employees. If the employee retires, resigns, or is terminated before collection of the indebtedness is completed, the remaining indebtedness will be offset from any subsequent payments of any nature. If the debt cannot be satisfied from subsequent payments, then the debt will be collected according to the procedures for administrative offset pursuant to § 105-55.011 of this subpart.
(c) Types of collection. A debt may be collected in one lump sum or in installments. Collection will be by lump sum unless the employee is able to demonstrate to the program official who signed the notice letter that he or she is financially unable to pay in one lump sum. In these cases, collection will be by installment deductions. Involuntary deductions from pay may not exceed 15 percent of disposable pay.
(d) Methods of collection. If the debt cannot be collected in one lump sum, the debt will be collected by deductions at officially established pay intervals from an employee's current pay account, unless the employee and the appropriate program official agree to an alternative repayment schedule. The alternative arrangement must be in writing and signed by both the employee and the appropriate program official.
1. (1) Installment deductions. Installment deductions will be made over the shortest period possible. The size and frequency of installment deductions will bear a reasonable relation to the size of the debt and the employee's ability to pay. However, the amount deducted for any period will not exceed 15 percent of the disposable pay from which the deduction is made, unless the employee has agreed in writing to the deduction of a greater amount. The installment payment normally will be sufficient in size and frequency to liquidate the debt in three (3) years or less, unless circumstances warrant a longer period. Installment payments of less than $100 per pay period will be accepted only in the most unusual circumstances.
2. (2) Sources of deductions. GSA will make salary deductions only from basic pay, special pay, incentive pay, retired pay, retainer pay, or in the case of an employee not entitled to basic pay, other authorized pay.
(e) Non-Salary payments. The receipt of collections from salary offsets does not preclude GSA from pursuing other debt collection remedies, including the offset of other Federal payments to satisfy delinquent non-tax debt owed to the United States. GSA will pursue, when appropriate, such debt collection remedies separately or in conjunction with salary offset.
(f) Interest, penalties and administrative costs. Interest, penalties and administrative costs on debts under this subpart will be assessed according to the provisions of § 105-55.016 of this subpart.