says truckstop
Black silhouettes of trucks and a bus.

Link icon Truck and Bus Regulation School Bus Menu

Requires: Owners of diesel-fueled school buses with a gross vehicle weight rating greater than 14,000 pounds are required to install diesel particulate filters from 2012 to 2014.

Owners must retire school buses manufactured before April 1, 1977, by January 1, 2012.

Note: School buses that cannot be retrofitted (e.g. 2-stroke engine buses), can delay their compliance until January 1, 2018. Reporting requirements apply until the school bus is brought into compliance. By January 1, 2018, these buses must be replaced, or repowered with an engine that can be retrofited.