AbstractIntroductionUnderstanding clinical reasoning is essential for patient care and medical education. Dual‐processing theory suggests that nonanalytic reasoning is an essential aspect of expertise; however, assessing nonanalytic reasoning is challenging because it is believed to occur on the subconscious level. This assumption makes concurrent verbal protocols less reliable assessment tools.MethodsFunctional magnetic resonance imaging was used to explore the neural basis of nonanalytic reasoning in internal medicine interns (novices) and board‐certified staff internists (experts) while completing United States Medical Licensing Examination and American Board of Internal Medicine multiple‐choice questions.ResultsThe results demonstrated that novices and experts share a common neural network in addition to nonoverlapping neural resources. However, experts manifested greater neural processing efficiency in regions such as the prefrontal cortex during nonanalytical reasoning.ConclusionsThese findings reveal a multinetwork system that supports the dual‐process mode of expert clinical reasoning during medical evaluation.