The OIG has issued a report entitled “Oversight of the Prescriber Identifier Field in Prescription Drug Event Data for Schedule II Drugs." Based on an audit of Prescription Drug Event (PDE) records for Schedule II drugs, the OIG found that approximately 228,000 PDE records with invalid prescriber identifiers accounted for about $20.6 million in gross drug costs in 2007. The OIG recommends that CMS take steps to ensure that Part D plan sponsors include a valid Drug Enforcement Administration number on all PDE records involving Schedule II drugs. CMS did not concur with the OIG’s recommendations, citing the need to ensure that Medicare beneficiaries have access to critical medications.