Although he had played small roles in several TV-movies and made his feature film debut in Sidney Lumet's "Just Tell Me What You Want" (1980), Gross was barely known in Hollywood circles, let alone to audiences, when he was cast as Steven Keaton, the liberal husband and father on "Family Ties". Eight seasons as Keaton followed, a period in which Gross was able to spend his hiatus in other roles, such as Gloria Vanderbilt's legal guardian in the NBC miniseries "Little Gloria: Happy at Last" (1982) and King Arthur in "A Connecticut Yankee in King Arthur's Court" (NBC, 1989). Gross also appeared in number of "In the Line of Duty" TV-movies, including a heralded turn as a murderer in "In the Line of Duty: The F.B.I. Murders" (NBC, 1988). Subsequent appearances found him playing FBI agents. Additionally, the actor continued to appear onstage in productions in Los Angeles.
Gross played love interest to Lily Tomlin in the 1988 feature "Big Business" and went on to co-star with Reba McEntire as a survivalist couple battling giant maggots in "Tremors" (1990). He then took time off to indulge in his love for model trains and railroad memorabilia. After a two year absence, Gross was back in front of the camera with "Alan and Naomi" as well as a host of TV-movies.
He is the brother of Mary Gross, a comic actress who spent several seasons on NBC's "Saturday Night Live".