The term “adverse event” describes harm to a patient as a result of medical care, such as infection associated with use of a catheter. The term “never events” refers to a specific list of serious events, such as surgery on the wrong patient, that the National Quality Forum (NQF) deemed “should never occur in a healthcare setting.” The Tax Relief and Healthcare Act of 2006 (the Act) mandates that the Office of Inspector General (OIG) report to Congress regarding the incidence of never events among Medicare beneficiaries, payment by Medicare or beneficiaries for services in connection with such events, and Centers for Medicare & Medicaid Services (CMS) processes to identify events and deny payment. This report is one in a series to fulfill requirements in the Act. OIG work on this topic will continue through 2009.