Friedman’s work is represented in major museums and galleries around the world, including the Museum of Modern Art and the Guggenheim Museum in New York, the Tate Modern in London, the Hood Museum of Art at Dartmouth College, and Staatsgalerie Stuttgart. The University of Iowa Alternative Traditions in the Contemporary Arts is the official repository of Friedman’s art work, personal papers, and research notes. Archiv Sohm at Staatsgalerie Stuttgart and the Mandeville Department of Special Collections at the University of California hold extensive collections of his work and papers from the 1960s and 1970s.