Diagnostic excellence is a priority of both patients and individual clinicians, yet does not seem to be afforded the same attention by health care systems. Autopsy data from 2 Swedish hospitals revealed that 30% of 2410 cases had clinically significant undiagnosed diseases.1 A review of methods used to estimate the rate of diagnostic error suggested that diagnostic errors are more common than medication errors.2 Even for conditions that are considered “easy” to detect, such as hypertension, 1 estimate suggested that 10% of US adults may have high blood pressure that is undiagnosed.3 Failure to make diagnoses expeditiously leads to prolonged uncertainty and may result in costly unnecessary tests and procedures, delayed treatment, and increased risk of morbidity and mortality. If diagnoses are forgone in favor of empirical treatment, patients may receive ineffective or potentially harmful treatments. Given this, a key question is why physicians would take shortcuts on diagnostic workups and rely on guesses and intuition when initiating treatments when it is possible to make accurate diagnoses and deliver evidence-based care.