At the most basic level, compendia are drug information resources intended to aid clinicians in making “informed treatment decisions, especially in difficult and complex cases.”1 They were not intended for use in determining reimbursement of medications for the public and private healthcare insurance sectors. Nevertheless, this responsibility was assigned by the Centers for Medicare & Medicaid Services (CMS) in a 1993 law that requires Medicare plans to use 1 of 4 national compendia to determine coverage and pay for “off-label uses of anticancer drugs for Medicare beneficiaries.”2