Diagnostic uncertainty is common and can lead to missed or delayed diagnoses. This retrospective medical record review study examined cases where primary care providers sought diagnostic input from subspecialists. Investigators compared the final diagnosis from the subspecialty visit with the presumed diagnosis at the time of the initial subspecialty referral. They found that the diagnosis differed substantially in about one-fifth of cases following the subspecialty consultation. Costs were higher for cases with substantively different diagnoses compared to cases where subspecialists confirmed or further clarified diagnoses. The authors conclude that subspecialty access is critical to timely and accurate diagnosis. A recent WebM&M commentary discussed how cognition can influence diagnostic decision making.