The school says Heathcote died Monday in Spokane, Washington.
Spartans coach Tom Izzo was hired by Heathcote and was promoted to replace him when he retired in 1995.
Heathcote won three Big Ten titles and appeared in nine NCAA tournaments during his 19-year career at Michigan State. He got his start as a head coach in college at Montana in 1971.
Izzo says the basketball world is a sadder place because of his mentor's death, adding no one cared more about the welfare of the game than Heathcote. Izzo helped the Spartans win their second NCAA basketball title in 2000 and often leaned on Heathcote for advice, counsel and humor.