Clinical distractions may account for 43% of medication errors. "Silent errors" in Computer Provider Order Entry (CPOE) warrant a new perspective for interruption analysis. We developed a taxonomy of interruptions in the context of CPOE. In two hours of observed CPOE use by residents during Medical Intensive Care Unit (MICU) rounds, one distraction or interruption occurred approximately every 5 minutes and preceded 2 order entry errors. Future analysis of the proposed taxonomy in a variety of clinical settings may help to understand "silent errors" and identify possible informatics interventions to prevent such errors.