Kerner played in Broadway productions My Old Friends (1979) and Chronicle of a Death Foretold (1995), originating the role of Xius, a widower. Off-Broadway, his credits include Don Juan of Seville (1989), and La Carreta (The Oxcart, 1992); of the latter, The New York Times praised Kerner for his performance "as a grandfather who embodies the values [playwright] Marques cherished most." On television, his work ranged from appearances on early TV shows like One Step Beyond (1959) to 1970s and 80s action series, including Miami Vice and multiple episodes of Kojak and The Equalizer.