In 1933, when Adolf Hitler came into power, the Jewish family moved from Germany to Paris, where Lukas studied piano with Lazare Lévy, composition with Noël Gallon, orchestration with Felix Wolfes, and flute with Marcel Moyse.

He studied at the Curtis Institute of Music in Philadelphia, with Isabelle Vengerova (piano), Rosario Scalero (composition) and Fritz Reiner (conducting).

[3] Foss is grouped in the "Boston school" along with Arthur Berger, Irving Fine, Alexei Haieff, Harold Shapero, and Claudio Spies.

Foss and his wife were separated for almost five years from 1968 to 1972, during which Cornelia was the lover of pianist Glenn Gould and moved with the two children to Toronto, an arrangement that she later called, "a perfect triangle".

[8] Foss, who had Parkinson's disease in his final years, died at his home in Manhattan on February 1, 2009, aged 86, of a heart attack.