According to the Hollywood Reporter, Gam died from respiratory failure at Cedars-Sinai Medical Center in Los Angeles on Tuesday.
During her acting career, Gam starred in films like Saadia, Sign of the Pagan and King of Kings.
Gam also played the real life role of one of Grace Kelly‘s bridesmaids when the actress wed Prince Ranier in 1956, THR adds.
Aside from her on screen roles, Gam also starred in a handful of stage productions including Wit & Wisdom, Hamlet and There’s a Girl in My Soup.
Gam was married to Lumet – who directed 12 Angry Men and Dog Day Afternoon – from 1949 until 1955 when the pair divorced and she married Thomas Guinzberg a year later in 1956.
According to THR she is survived by a daughter and a son, as well as film producer Kate Guinzberg, and novelist Michael Guinzberg.
Funeral arrangements have not yet been made.