 Kiefel rode for American professional teams such as 7-Eleven, Motorola, Coors Light and Saturn.His wins included the 1985 Trofeo Laigueglia and the 1987 Tour of Tuscany.He became the first American stage winner in a Grand Tour when he won stage 15 (from L'Aquila to Perugia) in the 1985 Giro d'Italia.