This endorsement is required for driving a school bus. To receive this endorsement, applicants must pass a written test. The test consists of 20 multiple choice questions. To pass, the applicant must answer at least 16 questions correctly. Test questions come from the Commonwealth of Pennsylvania Commercial Driver’s Manual and Pennsylvania School Bus Driver Manual. Questions come from chapters covering: Passengers and School Buses. The School Bus endorsement can be used with the Class A, B or C CDL.