42 C.F.R. § 428.403
(a) General. Manufacturers of Part D rebatable drugs may submit a Suggestion of Error about the information in their Preliminary Rebate Report and the report detailing the preliminary reconciliation of the rebate amount to CMS, for its discretionary consideration, if the manufacturer believes that there is a mathematical error or errors to be corrected before the Rebate Report or a subsequent reconciliation, as applicable, is finalized.
(d) Notice.