Background: The 2015 Institue of Medicine report Improving Diagnosis in Health Care highlighted that diagnostic errors cause patient harm and that improvement in the diagnostic process requires better collaboration among physicians and laboratory professionals. The purpose of this study is to understand why physicians do not contact laboratory professionals when facing diagnostic challenges and identify opportunities for laboratory professionals to become more recognized members of the clinical care team. Methods: A random sample of 31,689 physicians from the American Medical Association Masterfile were surveyed about diagnostic challenges in laboratory test ordering and results interpretation, solutions to these challenges, and interactions with laboratory professionals. Results: We received responses from 1768 physicians (5.6%). When faced with diagnostic challenges, they reported using electronic resources because they find it difficult and time-consuming to contact the laboratory. Only 20% had an effective way to access laboratory professionals, mostly seeking help for logistical but less for clinical issues. Continuing medical education, professional articles, and updates from the laboratory were helpful. Conclusions: Laboratory professionals have an opportunity to play a greater role in the diagnostic process by becoming active members of the clinical care team, beyond providing results. This study provides strategies to increase laboratory professionals' role in the diagnostic process.