(a) The Secretary may reopen and revise a reimbursement determination upon the Secretary's own motion or upon the request of a sponsor:
(1) Within 1 year of the reimbursement determination for any reason.
(2) Within 4 years of a reimbursement determination for good cause.
(3) At any time, in instances of fraud or similar fault.
(b) For purposes of this section, the Secretary does not find good cause if the only reason for the revision is a change of legal interpretation or administrative ruling upon which the determination to reimburse was made.
(c) A decision by the Secretary not to revise a reimbursement determination is final and binding (unless fraud or similar fault is found) and cannot be appealed.