All vehicles with a seating capacity including the driver of ten persons or less are not required to meet school bus specifications. Such vehicles regularly used to transport students to and from school or in connection with school activities must carry the approved school bus first-aid kit, fire extinguisher, and highway warning kit. These vehicles also must pass a safety inspection routinely conducted at the intervals outlined in WAC 392-143-035.

School districts may use an MFSAB with a seating capacity of less than sixteen passengers, including the driver. An MFSAB may be used to transport students and is required to have Washington state patrol inspections, initial and annual, for the appropriate class vehicle. An MFSAB must not be used in home-to-school transportation, or where any stop configuration would require the use of alternately flashing school bus warning lights if the vehicle were a school bus. An MFSAB must be equipped with a lap-shoulder belt or other passenger securement system that meets the requirements set forth in the Washington state school bus specifications manual in all seating positions and must not be painted school bus yellow. An MFSAB must carry the approved school bus first-aid kit, fire extinguisher, and highway warning kit. All drivers of an MFSAB must have a school bus driver's authorization in accordance with chapter 392-144 WAC.

All other vehicles used to transport students with a manufacturer rated seating capacity including the driver greater than ten persons are required to meet school bus specifications.