Citing a recent Health and Human Services (HHS) Office of Inspector General (OIG) report that found Medicaid may have lost $1.3 billion in base and inflation-adjusted rebates for the top 10 potentially misclassified drugs from 2012 to 2016, Republican and Democratic leaders of the Senate Finance Committee and the House Energy and Commerce Committee wrote to the Centers for Medicare & Medicaid Services (CMS) to voice their concerns about the misclassification of prescription drugs under the rebate program.