He was elected a Fellow of the Explorers Club in 1979, a Fellow of the American Association for the Advancement of Science in 1995 and a Fellow of the American Physical Society in 2004. He was Chairman and member of the Board of the International Gemini Project during 1996–1999 and was President of the American Astronomical Society during 1998–2000. During 2001, he served as a member of the National Research Council Committee on the Organization and Management of Research in Astronomy and Astrophysics (COMRAA). Gehrz is a past chair and member of the NSF/NASA Astronomy and Astrophysics Advisory Committee (AAAC). He currently serves as a member of the NASA James Webb Space Telescope (JWST) Product Integrity Team (PIT) that reviews the optical telescope assembly and is Chair of the NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) Users Group (SUG). Gehrz is the University of Minnesota representative to the Universities Space Research Association (USRA) Council of Institutions.