42 CFR § 456.709 - Retrospective drug use review.
(a) General. The State plan must provide for a retrospective DUR program for ongoing periodic examination (no less frequently than quarterly) of claims data and other records in order to identify patterns of fraud, abuse, gross overuse, or inappropriate or medically unnecessary care among physicians, pharmacists, and Medicaid beneficiaries, or associated with specific drugs or groups of drugs. This examination must involve pattern analysis, using predetermined standards, of physician prescribing practices, drug use by individual patients and, where appropriate, dispensing practices of pharmacies. This program must be provided through the State's mechanized drug claims processing and information retrieval systems approved by CMS (that is, the Medicaid Management Information System (MMIS)) or an electronic drug claims processing system that is integrated with MMIS. States that do not have MMIS systems may use existing systems provided that the results of the examination of drug claims as described in this section are integrated within their existing system.
(b) Use of predetermined standards. Retrospective DUR includes, but is not limited to, using predetermined standards to monitor for the following:
(3) Appropriate use of generic products, that is, use of such products in conformity with State product selection laws.
(4) Therapeutic duplication as described in § 456.705(b)(1).