Central line–associated bloodstream infections (CLABSI) can be nearly eliminated through implementation of a safety bundle. Prior studies have argued that these interventions are cost effective because the money saved by preventing infections is greater than the cost of the program itself. This study substantiates these significant savings in hospital costs by avoiding CLABSI, but it finds a concomitant marked decrease in hospital reimbursement rates. Under the fee-for-service system, hospitals net a margin of approximately $55,000 for patients that develop CLABSI versus $6,500 in those that do not. Therefore, the business case for this quality improvement measure is purely for the payers, and the decrease in hospital margins for line infections sets up a "perverse incentive" for medical centers. This study adds to recent similar findings that surgical complications also often result in net profits for medical centers.