29 CFR §102.163

1. (a)The Agency must afford the debtor the opportunity to repay the debt or enter into a repayment plan which is agreeable to the Agency and is in a written form signed by the debtor. The Agency may deem a repayment plan to be abrogated if the debtor, after the repayment plan is signed, fails to comply with the terms of the plan.
2. (b)The Agency has discretion and may exercise sound judgment in determining whether to accept a repayment agreement in lieu of administrative offset.