Heche will also have to pay 75 percent of Homer's private-school tuition. The couple agreed to split the cost of any "agreed upon extracurricular activities" for their son.
Heche, 39, and Laffoon, 34, were married Sept. 1, 2001. He filed for divorce on Feb. 2, citing irreconcilable differences.
Heche starred in TV's "Men in Trees." She and Laffoon, a cameraman, met while working on a documentary about Ellen DeGeneres - with whom Heche was romantically linked for three years.