Gelbwaks was the first actor to play the role of Chris Partridge. He left the program (and the business) after the first season, and was replaced by Brian Forster in the summer of 1971. According to his Partridge Family co-star David Cassidy, Gelbwaks "had a personality conflict with every person in the cast and the producers". He left the Business because he and his family moved to Reston, Virginia, a suburb of Washington, D.C., where they remained for a year and a half before moving again to Connecticut and later, Potsdam, NY, where he went to college, graduating in 1982. His father, Norman, taught Computer Science at the State University of New York at Potsdam. Gelbwaks worked in the computer industry from 1982 to 1999, studied Business at Columbia University, and is now a management consultant. He has appeared in a couple of Partridge Family reunions with his television family, including "Chris #2" (Brian Forster).

Gelbwaks became a computer analyst in 1983 while studying chemistry at UC Berkeley. He is married to Patricia Polander, lives in New Orleans, and works as a Business and Technology planner.