Adverse event (AE) investigations typically only include organizational or regulatory professionals. This study included English-, Spanish-, and Cantonese-speaking patients and caregivers who receive care in a California public health system. In interviews and focus groups, participants were presented with two exemplars of an ambulatory AE and asked to describe potential contributing factors and preventive measures. Themes identified include: (1) patients and teams have specific safety responsibilities; (2) proactive communication drives safe ambulatory care; (3) barriers related to limited resources contribute to ambulatory AEs. This study demonstrates that patients and caregivers can make important contributions to AE reviews.