After graduating from Central, James Ehrhardt went on to attend the University of Iowa and graduated Magna Cum Laude with a double major in Physics and Mathematics. In 1970 he earned a Ph.D. in Physics from the University of California, Berkeley. He and his wife Pamela moved to Iowa City where he obtained a faculty position in the Department of Radiology at the University of Iowa.

James was the first physicist in the state of Iowa to be certified by the American Board of Radiology. He served as the first Director of the Magnetic Resonance Imaging Center at the University of Iowa Hospitals and Clinics and as Chair of the University's Radiation Protection Committee.