Martin Mucci is retiring as CEO at Paychex, effective October 14, but he will stay on as chairman of the board.
President and Chief Operation Officer John Gibson, Jr. will remain president and take over as CEO.
Paychex founder Tom Golisano thanked Mucci for his leadership.
Golisano says the board is sincerely grateful for Mucci's many contributions and looks forward to his continued stewardship as chairman.
Gibson joined Paychex in 2013 as senior vice president of service, leading the operations of all Paychex business divisions.
He was promoted to president and COO last year.