The Medicaid agency must assure appropriate audit of records if payment is based on costs of services or on a fee plus cost of materials. 42 C.F.R. §447.202
(a)Basis and purpose. This section, based on section 1902(a)(4) of the Act, prescribes the kinds of records a Medicaid agency must maintain, the minimum retention period for such records, and the conditions under which those records must be provided or made available. (b)Content of records. A State plan must provide that the Medicaid agency will maintain or supervise the maintenance of the records necessary for the proper and efficient operation of the plan. The records must include all of the following:
A State plan must provide that the Medicaid agency will- (a) Submit all reports required by the Secretary; (b) Follow the Secretary's instructions with regard to the form and content of those reports; and (c) Comply with any provisions that the Secretary finds necessary to verify and assure the correctness of the reports. 42 C.F.R. §431.16 44 FR 17931, Mar. 23, 1979