According to a recent OIG report, Medicare Part D inappropriately paid $25 million for Schedule II drugs billed as refills in 2009, since federal law prohibits the refilling of Schedule II controlled substances. The OIG found a high incidence of invalid prescribers for Schedule II refills. The OIG speculates that some of these refills may reflect inaccurate billing, however, such as long-term-care pharmacies incorrectly billing these drugs as refills when they actually were partial fills. Because 194 out of 270 Part D sponsors paid for at least one Schedule II drug billed as a refill, the OIG concludes that “many sponsors do not have adequate controls to prevent these refills.” Based on these finding, the OIG recommends that CMS: (1) issue guidance to plan sponsors to prevent billing of Schedule II refills and to ensure accurate billing of partial fills; (2) exclude Schedule II refills when calculating payments to sponsors; (3) monitor sponsors to ensure that they validate prescriber numbers for Schedule II drugs; and (4) follow up on sponsors, pharmacies, and prescribers with high numbers of refills.