Failure to properly follow up on test results can result in missed or delayed diagnoses. This study from the Veterans Affairs (VA) system reveals the clinical impact of inadequate care processes for patients with urgent follow-up needs. By analyzing 111 root cause analyses of diagnostic error cases in the outpatient setting, the authors determined that poorly coordinated care—arising from a lack of systems to track patients needing urgent evaluation, insufficient follow-up of abnormal test results, and inadequate communication between clinicians—contributed to most of the missed or delayed diagnoses. Although electronic medical records (EMRs) should facilitate responding to abnormal test results, prior VA studies have shown that a small but clinically significant proportion of abnormal laboratory tests and radiology studies are not acted upon in a timely fashion (despite the VA having a fully integrated EMR for more than a decade). The authors advocate for refining EMR systems to better facilitate communication between clinicians and for emphasizing teamwork training in the outpatient setting.