42 CFR § 422.326 - Reporting and returning of overpayments.
(a) Terminology. For purposes of this section -
Overpayment means any funds that an MA organization has received or retained under title XVIII of the Act to which the MA organization, after applicable reconciliation, is not entitled under such title.
(b) General rule. If an MA organization has identified that it has received an overpayment, the MA organization must report and return that overpayment in the form and manner set forth in this section.
(c) Identified overpayment. The MA organization has identified an overpayment when the MA organization has determined, or should have determined through the exercise of reasonable diligence, that the MA organization has received an overpayment.
(d) Reporting and returning of an overpayment. An MA organization must report and return any overpayment it received no later than 60 days after the date on which it identified it received an overpayment, unless otherwise directed by CMS for purposes of § 422.311.