The purpose of this project is to develop and test a measure of diagnostic performance for emergency department patients admitted with pneumonia to enhance accountability and create a path to sustainable improvement of clinician diagnostic skills. ED physicians report diagnostic quality as an important source of self-efficacy and a strong desire for follow-up information about their patients, but in the current healthcare system, they receive little or no consistent feedback. Diagnostic excellence requires not only knowledge and experience, but engagement and motivated self-improvement around intuitive reasoning. Individualized performance feedback that leverages information about individual patients enhances core motivational processes that are central to intrinsically motivated learning. We hypothesize that timely, accurate, and consistent feedback that increases front-line providers’ access and attention to patients’ final diagnoses will improve diagnostic reasoning skills, increase appropriate use of diagnostic tests, enhance documentation and communication about diagnoses with patients and other providers, and improve care.