CDL School Bus (S) Endorsement Practice Test Guide

The school bus (S) endorsement has three separate requirements under federal law: you must already hold the passenger (P) endorsement, pass a school bus knowledge test covering loading, evacuation, and railroad crossings, and pass a skills test in an actual school bus matching the vehicle group you’ll drive. Most states run the knowledge portion at 20 questions with an 80 percent passing score, though Illinois requires 90 percent for this specific test, ten points higher than every other Illinois CDL knowledge exam.

The S endorsement stacks on top of the P endorsement rather than replacing it, so a driver needs to clear both knowledge tests and both skills components before touching a yellow bus. Entry Level Driver Training (ELDT) also applies: anyone getting the S endorsement for the first time must complete training through a provider on FMCSA’s Training Provider Registry before testing, a federal requirement in place since February 7, 2022.

CDL is the name of a real license category issued by state driver-licensing agencies. This page is not affiliated with FMCSA or any state DMV, and every practice question below was written from scratch against the federal regulation, not copied from any exam bank.

What does 49 CFR 383.123 actually require?

Federal rule 49 CFR 383.123 sets a three-part structure for the school bus endorsement. First, the applicant must already have passed the knowledge and skills tests for the passenger endorsement. Second, the applicant needs a separate school bus knowledge test. Third, the applicant must pass a skills test driven in a school bus that matches the vehicle group (Class A, B, or C) they intend to drive (eCFR, 49 CFR 383.123). Skipping any one of the three pieces means the endorsement isn’t issued.

What’s on the school bus knowledge test?

The federal knowledge list covers four areas. Loading and unloading children, including the safe use of stop signal devices, external mirror systems, and flashing warning lights required on school buses. Emergency exits and evacuating passengers safely in an emergency. State and federal rules for safely crossing railroad-highway grade crossings. And general operating practices not otherwise specified in the first three topics (eCFR, 49 CFR 383.123(a)(2)). New York’s CDL manual folds the school bus material into its own dedicated Section 10, separate from the general passenger section, since the topics don’t overlap with regular bus operation (NY DMV, Commercial Driver’s Manual, Section 10: School Bus).

Do you need the passenger endorsement first?

Yes, and this trips up more applicants than any other part of the process. The passenger (P) endorsement has its own knowledge test (loading and unloading passengers, emergency exits, emergencies, railroad crossings, braking) and its own skills test, and both have to be complete before the school bus knowledge test even applies. New York specifically requires the school bus endorsement “in addition to the P endorsement” for any bus with a GVWR over 26,000 pounds or designed to seat 15 or more adult passengers excluding the driver (NY DMV, New York State Commercial Driver’s Manual). Trying to schedule the school bus knowledge test without a passenger endorsement already on file just gets the appointment rejected.

Does ELDT apply to the school bus endorsement?

Yes. Entry-Level Driver Training applies to anyone obtaining a passenger, school bus, or hazardous materials endorsement for the first time, on top of applying to every first-time Class A or B CDL applicant. The rule took effect February 7, 2022 and isn’t retroactive: drivers who already held the S endorsement before that date don’t need to redo training for it (FMCSA, Entry-Level Driver Training). Training has to come from a provider listed on FMCSA’s Training Provider Registry (tpr.fmcsa.dot.gov), and the completion record has to show up there before a state will schedule the knowledge or skills test.

Passing score by state: general rule vs. the Illinois exception

Item	Most states	Illinois
General knowledge test	80%	80%
Endorsement knowledge tests (passenger, hazmat, tank, etc.)	80%	80%
School bus knowledge test	80%	90%

Illinois sets every CDL knowledge test at an 80 percent passing score, with one named exception: the school bus test requires 90 percent (Illinois Secretary of State, Commercial Driver’s License (CDL) and Commercial Learner’s Permit (CLP)). That’s a 10-point gap most study guides don’t call out, and it means an Illinois applicant who’d pass the school bus test in most other states, at 82 or 85 percent, would fail it at home.

Run through timed sets like the ones below in the CDL Practice Hub school bus endorsement practice quiz before test day, since the four knowledge areas above get tested in scenario form, not as simple recall.

Sample school bus endorsement practice questions

These are original questions written from the federal knowledge list in 49 CFR 383.123, not copied from any state or third-party exam bank.

1. What endorsement must a driver already hold before taking the school bus knowledge test? The passenger (P) endorsement, with both its knowledge and skills tests already passed.

2. What warning devices does the loading and unloading knowledge area cover? Stop signal devices, external mirror systems, and flashing lights and other passenger safety devices required on school buses by state or federal law.

3. True or false: the school bus skills test can be taken in any CDL-class vehicle, since the knowledge test is the harder requirement. False. The skills test must be driven in a school bus of the same vehicle group the applicant is applying to drive.

4. What must a school bus driver confirm before crossing railroad tracks without a gate or signal? That the tracks are clear in both directions, following the state and federal procedures required specifically for railroad-highway grade crossings.

5. Does the school bus endorsement replace the passenger endorsement? No. It stacks on top of the P endorsement; a driver needs both, not one instead of the other.

6. Since February 7, 2022, what federal training is required before a first-time school bus endorsement test? Entry-Level Driver Training (ELDT) completed through a provider listed on FMCSA’s Training Provider Registry.

7. What passing score does Illinois require on its school bus knowledge test? 90 percent, ten points higher than the 80 percent standard Illinois uses for every other CDL knowledge test.

8. What is a driver expected to know about emergency exits on a school bus? How to safely evacuate passengers in an emergency, including the location and operation of exits beyond the main door.

9. A driver held the S endorsement before February 7, 2022. Do they need to complete ELDT to keep it? No. The ELDT rule isn’t retroactive, so endorsements issued before that date aren’t affected.

10. What vehicle threshold does New York use to define a school bus requiring the S endorsement? A GVWR of more than 26,000 pounds, or a design capacity of 15 or more adult passengers excluding the driver.

If a study packet covering both the passenger and school bus knowledge areas in one place sounds useful, that’s what the CDL Practice Hub CDL study guide is built for.

FAQ

How many questions are on the school bus knowledge test? Most states run around 20 questions, though the exact count is set by each state, not federal law. Confirm the number against your own state’s CDL manual before test day.

Can I take the school bus knowledge test before the passenger test? No. Federal rule 383.123 requires the passenger endorsement, both knowledge and skills, to already be in place before the school bus knowledge test applies.

Does every state require 80 percent to pass the school bus test? No. Illinois is a documented exception at 90 percent. Most other states use the standard 80 percent CDL passing threshold, but always confirm against your own state manual.

Do I need ELDT if I’m just adding the S endorsement to an existing CDL? Yes, if this is your first time getting the S endorsement and it’s issued on or after February 7, 2022. Prior CDL experience with other endorsements doesn’t exempt you from ELDT for a new one.

What does the school bus skills test check that the passenger skills test doesn’t? It has to be performed in an actual school bus of the matching vehicle group, testing bus-specific procedures like the loading and evacuation practices covered in the knowledge test, not just general passenger-vehicle handling.