Most patient safety research and initiatives have focused on the hospital environment, despite the fact that much of health care is delivered in outpatient settings. This technical brief explores gaps in the evidence base that hinder understanding of safety concerns and factors unique to ambulatory care. The evidence review supports use of pharmacist interventions to augment medication safety in outpatient settings. The authors also found that electronic health records have mixed effects on ambulatory safety. Key informants interviewed for the brief noted that studies on patient engagement and diagnostic error are lacking.