Identifying and measuring diagnostic error remains an ongoing challenge. Trigger tools are frequently used in health care to detect adverse events. Researchers describe the Safer Dx Trigger Tools Framework as it applies to the development and implementation of electronic trigger tools that use electronic health record data to detect and measure diagnostic error. The authors suggest that by identifying possible diagnostic errors, these tools will help elucidate contributing factors and opportunities for improvement. They also suggest that, if used prospectively, such tools might enable clinicians to take preventive action. However, to design and implement these electronic trigger tools successfully, health systems will need to invest in the appropriate staff and resources. A past PSNet perspective discussed ongoing challenges associated with diagnostic error.