Dr. Irby is professor emeritus of medicine and an educational scientist in the Center for Faculty Educators at University of California, San Francisco (UCSF).

His research is on faculty development, the learning environment, clinical teaching, and leading organizational change.

From 1997–2011, he served as vice dean for education and director of the Office of Medical Education in the UCSF School of Medicine. From 2006–2010, he was also a senior scholar at The Carnegie Foundation for the Advancement of Teaching, where he co-directed a national study on the professional preparation of physicians. From 1972–1997, he was a professor of medical education at the University of Washington.

For his research and leadership in academic medicine, he has received awards from the Association of American Medical Colleges, the American Educational Research Association, the National Board of Medical Examiners, the Karolinska Institutet in Stockholm, Harvard Medical School, and Vanderbilt School of Medicine, among others. 

He earned a Masters of Divinity from Union Theological Seminary in 1970, a doctorate in education from the University of Washington in 1977, and completed a postdoctoral fellowship in academic administration at Harvard Medical School in 1983.