Rubenstein`s acting career was brief by Hollywood standards. After making his film debut in the 1976 thriller Dark Sunday, he appeared on an episode of Kojak along with Star Trek: Voyager`s Robert Picardo in 1977. Later in 1977, Rubenstein appeared in the TV movie Contract on Cherry Street with ENT guest stars Michael Nouri and Tucker Smallwood. In 1979, he was a regular on the short-lived CBS situation comedy series Working Stiffs, appeared on the CBS drama series The White Shadow with Madge Sinclair, and in an episode of the hit sitcom Taxi, along with series regular Christopher Lloyd and Dick Miller. His first major studio film was the 1979 musical drama The Rose, which also featured Jonathan Banks. In 1984, Rubenstein was seen in the TV movies Getting Physical (with Earl Boen, William Boyett, and an uncredited Spice Williams) and Gone Are the Days (directed by Gabrielle Beaumont and featuring Bibi Besch, Ted Gehring, and Olaf Pooley). In addition, he made the first of two appearances on Night Court, the hit NBC comedy series starring John Larroquette; he made his second appearance on the show in 1986. In 1985, he appeared on Highway to Heaven (in an episode with Anthony Zerbe) and appeared on the show again the following year.
Rubenstein had a small role in the 1982 film The Last American v*rgin, starring Lawrence Monoson. In 1984, he appeared alongside Vincent Schiavelli in the film Kidco. He also had a small role in the musical comedy film Rhinestone that same year, along with Chip Heller and Leslie Morris. In 1985, Rubenstein had a supporting role in the independent film The Boys Next Door, as did Christopher McDonald. In 1989, he appeared in three films: The Runnin` Kind with Julie Cobb, James Cromwell, and Kenneth Tigar; My Mom`s a Werewolf with John Schuck; and Tango & Cash with Marc Alaimo, Roy Brocksmith, Richard Fancy, Teri Hatcher, Clint Howard, Leslie Morris, Glenn Morshower, and Michael J. Pollard. Rubenstein then appeared in 1990`s RoboCop 2, along with Bill Bolender, Roger Aaron Brown, Gabriel Damon, Robert DoQui, John Glover, Galyn Görg, Stephen Lee, Tzi Ma, Jeff McCarthy, Mark Rolston, and star Peter Weller. Rubenstein had quite possibly his largest film role in the 1991 comedy Another You, opposite Craig Richard Nelson, Michael J. Pollard, Vincent Schiavelli, Vanessa Williams, and Biff Yeager. The following year, he made his final television appearance, in the final episode episode of the short-lived situation comedy Drexell`s Class, starring Dakin Matthews. Rubenstein died three months after this episode was aired.