Used school buses are generally sold when they are no longer useful to a school system. Many school systems retire buses based on mileage, so often buyers can find used buses that have no problems beyond their mileage exceeding the school systems' own regulations. Of course, although the school system may say there's nothing mechanically wrong with a bus, it's still a good idea to have an inspection performed.

Many non-profit organizations find themselves in need of some form of mass transportation but cannot afford to buy a new vehicle that carries a large amount of people. Used school buses are perfect because they are more affordable than new buses or luxury buses. School buses are built to safely transport children to and from school, so buyers know that they are purchasing a vehicle that is specifically built for safety.

Used buses are particularly ideal vehicles for churches and church groups. Such groups typically find that day trips are greatly simplified by having bus for transportation. Children's camps are also ideal candidates for school buses, due to the fact that not only day trips, but also certain camp facilities (like lakefronts) may require mass transportation.

Small used buses can make perfect vehicles for daycare and after-school programs that pick children up from schools. Many these smaller buses don't require commercial driver's licenses, so any staff member with a license can drive them.