Although computerized provider order entry in the outpatient setting was intended to prevent medication errors, the utility of this intervention may have been limited by alert fatigue. This observational study of outpatient clinical decision support found that approximately 53% of alerts in prescriptions were overridden, half of which should have been addressed. This study underscores the importance of improving clinical decision support to reduce inappropriate alerts in outpatient settings. A recent AHRQ WebM&M commentary highlights strategies to prevent alert fatigue.