In Diagnosis, John Barbieri, Benjamin French and Craig Umscheid investigate whether the use of a differential diagnosis (DDX) generator within a health care system leads to an increase in unnecessary testing and specialty consultation. By providing access to a broad differential, DDX generators can potentially help clinicians overcome cognitive biases by directing them to diagnoses they might not have considered otherwise. However, as the tool suggests numerous potential diagnoses, its use could result in an increase in unnecessary testing and specialty consultation, and associated costs and harms, particularly in the hands of less experienced clinicians. The authors of this study examine the use of a DDX generator across an academic health care system by month and compare the number of inpatient dermatology consults requested per month for the 12 months before versus the 18 months after the generator’s introduction. They find a median of 474 unique DDX sessions per month, most frequently conducted over mobile devices (35%) and through the inpatient electronic health record (34%). They find no statistically significant difference in the increase rate or absolute number of inpatient dermatology consults requested per month after the introduction of the DDX generator. The authors propose that, given the interest in using DDX generators, further research should continue to evaluate the impact of such tools on the quality and value of care delivered.