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Michael J. McPhaul, MD

Michael J. McPhaul, MD

Senior Medical Director, Endocrinology

Internal Medicine, Endocrinology


Michael J. McPhaul, MD is the Senior Medical Director for Endocrinology at Quest Diagnostics’ Nichols Institute. In his role, Dr McPhaul drives the development of new tools and diagnostic tests that assist in the comprehensive care of patients with prediabetes, metabolic syndrome, and diabetes mellitus, as well as the early identification of these ailments.


Dr McPhaul earned his medical degree from the University of Texas Southwestern Medical School. He completed an internship and residency in internal medicine at Parkland Memorial Hospital, followed by a research fellowship in biochemistry at Stanford University Medical Center.


Prior to joining Quest Diagnostics, Dr McPhaul was Professor of internal medicine in the division of endocrinology and metabolism and Associate Dean at the University of Texas Southwestern Medical Center. During his tenure there, his clinical research in the fields of androgen action and diseases of the pituitary led to an international reputation.


Dr McPhaul has published over 130 peer-reviewed manuscripts and 23 reviews and book chapters. His current research interests are centered broadly in the areas of endocrinology and metabolism, particularly steroid hormone measurements and the assessment of insulin resistance. Dr McPhaul serves as Editor in Chief for the Journal of Investigative Medicine High Impact Case Reports.


Dr McPhaul is board-certified by American Board of Internal Medicine. He is an active member of several professional societies, including the American Society of Clinical Investigation, American Association of Clinical Endocrinology, Endocrine Society, American Diabetes Association, Southern Society for Clinical Investigation, and the American Federation for Medical Research. 




Board Certifications

Internal Medicine


BA, University of Texas at Austin; MD, University of Texas Southwestern Medical School


Internal Medicine, Parkland Memorial Hospital


San Juan Capistrano, CA


Biochemistry, Stanford University Medical Center