42 C.F.R. § 433.304
As used in this subpart-
Discovery (or discovered) means identification by any State Medicaid agency official or other State official, the Federal Government, or the provider of an overpayment, and the communication of that overpayment finding or the initiation of a formal recoupment action without notice as described in § 433.316 .
Final written notice means that written communication, immediately preceding the first level of formal administrative or judicial proceedings, from a Medicaid agency official or other State official that notifies the provider of the State's overpayment determination and allows the provider to contest that determination, or that notifies the State Medicaid agency of the filing of a civil or criminal action.
Fraud (in accordance with § 455.2 ) means an intentional deception or misrepresentation made by a person with the knowledge that the deception could result in some unauthorized benefit to himself or some other person. It includes any act that constitutes fraud under applicable Federal or State law.
Overpayment means the amount paid by a Medicaid agency to a provider which is in excess of the amount that is allowable for services furnished under section 1902 of the Act and which is required to be refunded under section 1903 of the Act.
Provider (in accordance with § 400.203 ) means any individual or entity furnishing Medicaid services under a provider agreement with the Medicaid agency.
Recoupment means any formal action by the State or its fiscal agent to initiate recovery of an overpayment without advance official notice by reducing future payments to a provider.
Third party (in accordance with § 433.136 ) means an individual, entity, or program that is or may be liable to pay for all or part of the expenditures for medical assistance furnished under a State plan.
42 C.F.R. §433.304