He became an assistant professor at the University of Kentucky in 1970, and received the University of Kentucky Student Government's first Distinguished Teaching Award in 1973. He was denied tenure at Kentucky in 1977, and spent the next ten years in visiting positions at the University of Virginia, University of Cincinnati, University of North Carolina at Chapel Hill, and University of South Florida. After ten years without a tenure-track position, in 1987 he was hired as a tenured full professor at the University of Minnesota Duluth. In 1996, Fetzer received a Distinguished McKnight University Professorship from the University of Minnesota, a title that recipients retain until they retire from the University. He retired in 2006.