 He served as a county commissioner in Ingham County, Michigan (1983–88) and Washtenaw County, Michigan (2000–02).In 2004, he was elected as the Washtenaw County Clerk/Register of Deeds, the first Democrat in that position in 72 years.On March 22, 2014, following a U.S. District Court ruling that Michigan's ban on same sex marriage was unconstitutional, Kestenbaum was one of four Michigan county clerks to open for special hours while the ruling was in effect; his office issued marriage licenses to 74 gay and lesbian couples.