Rehr received a Ph.D. in Theoretical Condensed Matter Physics from Cornell University in 1972 working with 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. Rehr held visiting appointments at Cornell University (1986-88) working with Prof. K. Wilson, and at Lund University (spring 1994) with Prof. Lars Hedin. Rehr is also a Consulting Professor at the Stanford Synchrotron Radiation Lightsource, Co-coordinator of the DOE Computational Materials Science Network, and head of the Theoretical X-ray Beamline of the European Theoretical Spectroscopy Facility (ETSF). Rehr's research specialties are in condensed matter theory, with major interests in excited state electronic structure and the theory of x-ray and electron spectra. His group is especially known for the development of quantitative theories of EXAFS and other core-level x-ray and electron spectroscopies, as implemented in the FEFF codes.