Cyphers's first feature film was the 1974 movie Truck Turner, and he first worked with Carpenter in the 1976 action film Assault on Precinct 13, in which he played Starker, one of the ill-fated police officers gunned down by gang members.
Cyphers has appeared in numerous television productions. During the 1970s, he had a recurring role, as Hugo Muncy, in The Betty White Show, and he guest-starred in an episode of Gibbsville in 1976. In addition, he had guest roles in popular television series such as Barnaby Jones and The Dukes of Hazzard, and he played Drake in the 1977 mini series Roots.