In August 2008, the US Centers for Medicare & Medicaid Services (CMS) added deep venous thrombosis and pulmonary embolism after total knee arthroplasty (TKA) and total hip arthroplasty (THA) to the list of never events.1 If a patient experiences deep venous thrombosis or pulmonary embolism following one of these procedures, a portion of the payment made by CMS to hospitals is to be withheld. On the surface this decision seems to be a win-win for hospitals, clinicians, and patients. Venous thromboembolism (VTE) is a common cause of preventable harm,2 yet many hospitalized patients fail to receive adequate VTE prophylaxis.3 Accordingly, the strategy of using financial incentives to encourage better performance should result in fewer thrombotic events and consequently less morbidity and mortality related to VTE and its treatment.