Graduated from Columbia University. His mother, Carol Galligan is a Psychologist and Psychoanalyst in New York. His father, Arthur Galligan is retired as a partner in Dickstein Shapiro Morin & Oshinsky, in Washington.

Married Ling-Ling Hu Ingerick, 25 years old, on September 25, 2005 at the Yale Club in New York. She graduated from Tulane University. Her mother lives in Lady Lake, Florida and her father lives in Shoemakersville, Pennsylvania.
Parents divorced when Zach was 3 years old. Father is a lawyer. Ironically, he and his character Eric Rhodes from Cupid had February 14 (Valentine's Day) as their birthday.