DeSisto was a teacher, unlicensed therapist, and director for eleven years at The Lake Grove School on Long Island, New York. DeSisto disagreed with administrators of Lake Grove regarding their educational approach and was fired. In 1978 he secured funding mostly in the form of advance tuition payments, and direct donations, from the parents of former students of The Lake Grove School, and founded school. He founded the DeSisto at Stockbridge School in Stockbridge, Massachusetts for at risk teens in 1978.