Rehr received a Ph.D. in Theoretical Condensed Matter Physics from Cornell University in 1972 under the supervision of Prof. N. D. Mermin. A NATO postdoctoral fellowship at King's College London (1972-73), and a postdoctoral appointment with Prof. W. Kohn at University of California, San Diego, (1973-1975) followed. In 1975, Rehr joined the Department of Physics at the University of Washington. In visiting appointments Rehr worked with Prof. K. Wilson as a Visiting Scientist at Cornell University (1986-88) and with Prof. Lars Hedin at the Univ. of Lund (spring 1994). Rehr is also a Consulting Professor at Stanford Synchrotron Radiation Laboratory and a Co-coordinator of the DOE Computational Materials Science Network.
Professor Rehr's research specialties are in condensed matter theory, with major research interests involving excited state electronic structure and the theory of x-ray and electron spectra. His group is especially known for the development of x-ray spectroscopy codes. Rehr has over 200 scientific publications.