Clinical pharmacists can improve medication safety in the inpatient setting and—in response to a Joint Commission National Patient Safety Goal—are increasingly being deployed to prevent medication errors in the emergency department (ED). This cohort study found that ED pharmacists intervened in 10.1% of prescriptions written for patients discharged from the ED, in order to prevent errors and to optimize medical therapy. An earlier systematic review found that ED pharmacists were able to consistently identify potential medication errors and intervene appropriately.