Computerized provider order entry and decision support alert providers to potential prescribing errors and drug–drug interactions that may cause harm. However, prior research has shown that inappropriate medication alert overrides occur frequently and place patients at risk for adverse drug events (ADEs). The cost of these preventable ADEs on a national level remains unknown. Extrapolating medication order data from a random sample of patients at a single academic medical center over a 1-year period, researchers estimate that in 2014 there were 29.7 million adult inpatient discharges generating anywhere from 1.02 billion to 1.07 billion medication orders and leading to between 75.1 million and 78.8 million medication alerts, depending on the model used. They conclude that around 5.5 million medication alerts may have been inappropriately overridden and estimate the associated cost of treating the preventable ADEs resulting from these overrides to be between $871 million and $1.8 billion. A past Annual Perspective discussed the role of computerized provider order entry in patient safety.