Computerized provider order entry (CPOE) has been shown to decrease some adverse drug events (ADEs), but it has also introduced medication errors across multiple settings. This study examined the incidence of ADEs in an inpatient hematology–oncology setting in three timeframes: before CPOE, immediately following implementation, and 5 years later. Although researchers found a significant reduction in ADEs, some errors persisted. These results argue for continued development of decision support to enhance prescribing, particularly in high-risk environments such as inpatient cancer treatment. A past AHRQ WebM&M interview discussed how technology can augment medication safety.