Gerson began his career in the late '90s as a writer on TV shows including Duckman and The New Addams Family, before breaking out by co-writing Disney/Pixar's 2001 movie Monsters, Inc. He often worked with his writing partner Robert L. Baird, with whom he contributed to animated films like Chicken Little, Monsters University, Cars, Up, Big Hero 6 and Inside Out.
Gerson also voiced the janitors in Monsters, Inc. and the desk sergeant in Big Hero 6. At the time of his death, he was working on the upcoming Cars 3.
He is survived by his wife of 20 years, Beau Stacom; two children; his parents; and a sister.