Code of Federal Regulations Title 31. Money and Finance–Treasury § 31.321.18 Determination of loss

(a) That no final loss to the United States has occurred, and, accordingly, that the agent is relieved from liability for the payment, or that no claim for reimbursement shall be made unless and until a loss has been sustained;  or

(b) That while a final loss to the United States has occurred, the agent is not required to make reimbursement therefor, as the Secretary of the Treasury, or his designee, has determined that such loss resulted from no fault or negligence on the part of such agent;  or

(c) That a final loss to the United States has occurred, and that, the Secretary of the Treasury, or his designee, has been unable to make an affirmative finding that such loss resulted from no fault or negligence on the part of such agent, reimbursement must be made promptly, except where credit for the payment had not previously been extended.