As of 2025, the active fleet of NJ Transit Bus Operations consists of approximately 2800 buses which are housed and maintained at eighteen NJ Transit bus garages. NJ Transit and companies leasing buses from the state agency use various models of buses between 25 feet (7.6 m) (minibuses) and 60 feet (18 m) in length to provide local and commuter service within the state of New Jersey and adjacent parts of New York and Pennsylvania. NJ Transit introduced compressed natural gas (CNG) buses in 1999 and hybrid electric buses in 2007. As of the 2020s, NJ Transit began introducing clean diesel and battery electric buses to make the transition towards building a lower or zero-emission fleet. The rosters below list current and past buses purchased or otherwise acquired by NJ Transit for heavy duty fixed-route service.