After attending The Lawrenceville School, Forstmann graduated from Georgetown University in 1969, and began working at the Morgan Guaranty Trust Company.
In 1975, Forstmann joined Kohlberg Kravis Roberts & Co., a company with which he would later develop a rivalry.
[1] Forstmann served on the advisory boards of Georgetown University and Marymount College.
Forstmann was featured in the book about the bidding war, Barbarians at the Gate: The Fall of RJR Nabisco, and was portrayed in the subsequent film by actor Joseph Kell.
[2] Forstmann helped form the Inner-City Scholarship Fund of the Archdiocese of New York.