A Class S driver’s license isn’t a separate license class at all. The “S” is a school bus endorsement added to an existing commercial driver’s license, and federal regulations require it for anyone who drives a vehicle used to transport pre-primary, primary, or secondary students between home and school or to school-sponsored events.1eCFR. 49 CFR 383.5 – Definitions To earn it, you need a CDL in the right vehicle group, a passenger (P) endorsement, entry-level driver training from a registered provider, and passing scores on both a school-bus knowledge test and a skills test conducted in an actual school bus.
One boundary worth naming up front: the federal school bus definition doesn’t cover for-hire motor carriers. A charter company hired for a field trip under its own authority isn’t operating a “school bus” under these rules.1eCFR. 49 CFR 383.5 – Definitions
Which CDL Class the S Rides On
The S endorsement can sit on a Group A, B, or C CDL, but the group has to match the bus you plan to drive. Federal regulations split commercial vehicles this way:
- Group A covers combination vehicles with a gross combination weight rating of 26,001 pounds or more, where the towed unit exceeds 10,000 pounds.
- Group B covers single vehicles with a gross vehicle weight rating of 26,001 pounds or more, or such a vehicle towing a lighter trailer.
- Group C covers vehicles below those thresholds that are designed to carry 16 or more passengers (including the driver) or that transport placarded hazardous materials.
Most full-size school buses land in Group B because they weigh well over 26,001 pounds. Smaller buses that seat 16 or more but weigh less typically call for a Group C CDL.2eCFR. 49 CFR 383.91 – Commercial Motor Vehicle Groups Your skills test must be taken in a school bus from the same group as the one you intend to drive, so testing in a small bus won’t authorize you to drive a 40-foot conventional.3eCFR. 49 CFR 383.123 – Requirements for a School Bus Endorsement
The P Endorsement Comes First
This catches some applicants off guard. To qualify for the school bus endorsement, you first have to pass the knowledge and skills tests for a passenger vehicle (P) endorsement.3eCFR. 49 CFR 383.123 – Requirements for a School Bus Endorsement The P endorsement covers general skills for safely operating any vehicle designed to carry 16 or more people. The S endorsement layers on the school-bus-specific material: student loading zones, danger-zone awareness, evacuation procedures. Both codes must appear on your license before you can legally drive a school bus.
Who Qualifies
Age
Federal rules set the minimum age for interstate commercial driving at 21.4eCFR. 49 CFR 391.11 – General Qualifications of Drivers Since school routes almost always stay inside one state, some states allow applicants as young as 18 to drive intrastate, matching the federal floor for a Commercial Learner’s Permit.5eCFR. 49 CFR 383.71 – Driver Application and Certification Procedures In practice, most districts and state agencies still require school bus drivers to be 21, so verify your state’s rule before assuming 18 is enough.
Medical Certification
Every CDL holder has to pass a physical done by a provider listed on the FMCSA’s National Registry of Certified Medical Examiners. Not just any doctor will do. The examiner must be individually certified and searchable in the registry by name, location, or registry number.6Federal Motor Carrier Safety Administration. National Registry of Certified Medical Examiners The Medical Examiner’s Certificate is normally good for two years. Drivers with conditions like medication-controlled hypertension, diabetes, or sleep disorders may only get a one-year certificate, meaning more frequent exams.7Federal Motor Carrier Safety Administration. For How Long Is My Medical Certificate Valid?
Background Check
Federal CDL rules require applicants to certify they’re not currently disqualified and to disclose every state where they’ve been licensed to drive in the past ten years.5eCFR. 49 CFR 383.71 – Driver Application and Certification Procedures Fingerprinting and criminal history checks for school bus drivers are handled at the state level. Nearly every state requires them, and many require both a state and an FBI review. Costs typically run $40 to $100.
Entry-Level Driver Training
Since February 2022, anyone taking the S endorsement skills test for the first time has to complete Entry-Level Driver Training (ELDT) from a provider registered on the FMCSA’s Training Provider Registry.5eCFR. 49 CFR 383.71 – Driver Application and Certification Procedures The state licensing agency will confirm your training provider uploaded the certification to the registry before letting you take the skills test. Providers have until midnight of the second business day after training ends to file it.8Training Provider Registry. Training Provider Registry
The school bus ELDT curriculum has two parts, theory and behind-the-wheel, and neither carries a federally mandated minimum number of hours. The provider must cover every required topic and confirm you’ve demonstrated proficiency. Theory topics include danger zones and mirror use, loading and unloading procedures, post-crash response, emergency evacuation, railroad crossing safety, student management, bus security, and route planning. You need at least 80 percent on the theory assessment. Behind-the-wheel training covers the same material in practice and must happen in a school bus matching the vehicle group you plan to drive.9eCFR. 49 CFR Part 380 – Special Training Requirements
The Knowledge and Skills Tests
Commercial Learner’s Permit
The process starts with a CLP. To get one with S and P endorsements, you pass the general CDL knowledge test for your vehicle group plus the endorsement-specific written tests for both P and S.10eCFR. 49 CFR 383.93 – Endorsements The school bus knowledge test covers loading and unloading children, proper use of stop-signal devices and mirror systems, emergency exit and evacuation procedures, railroad crossings, and general operating practices.3eCFR. 49 CFR 383.123 – Requirements for a School Bus Endorsement
Skills Test
After ELDT and with your CLP in hand, you take a three-part skills test in an actual school bus. Every CDL skills test includes a pre-trip vehicle inspection, basic vehicle control maneuvers, and an on-road driving evaluation.11eCFR. 49 CFR 383.113 – Required Skills During the pre-trip portion, you walk around the bus identifying safety-related components and explaining what you’re checking: engine compartment, steering, brakes, suspension, wheels, and school-bus-specific features like emergency exits and student warning devices. Basic control tests starting, stopping, backing, and turning. The road test evaluates speed management, lane changes, railroad crossings, and student discharge zones.
Convictions That Will Disqualify You
Certain convictions strip your CDL, and with it the S endorsement, for long stretches or permanently. Some apply even to offenses committed in your personal car.
A first conviction for any of the following major offenses in a commercial motor vehicle triggers a one-year disqualification. A second conviction in any combination results in a lifetime ban:
- DUI or driving under the influence of a controlled substance, or a blood alcohol concentration of 0.04 or higher in a commercial vehicle.
- Refusing to submit to an alcohol test required under implied consent laws.
- Leaving the scene of an accident.
- Using a commercial vehicle to commit any felony.
- Causing a death through negligent operation of a commercial vehicle.
- Operating a commercial vehicle while your CDL is revoked, suspended, or canceled.
Two offenses carry lifetime disqualification with no reinstatement: using a commercial vehicle in drug trafficking, and using one in severe forms of human trafficking.12eCFR. 49 CFR 383.51 – Disqualification of Drivers
Serious traffic violations carry shorter disqualifications. Two convictions within three years bring a 60-day disqualification; three or more within three years bring 120 days. Those violations include excessive speeding (15 mph or more over the limit), reckless driving, improper lane changes, following too closely, texting while driving a commercial vehicle, and using a handheld phone while driving one.12eCFR. 49 CFR 383.51 – Disqualification of Drivers
Drug and Alcohol Testing
Before you drive a school bus for any employer, you must pass a pre-employment controlled substances test. That’s not a one-time hurdle. CDL holders in safety-sensitive positions are subject to random drug and alcohol testing throughout employment, post-accident testing when federal reporting thresholds are met, and reasonable-suspicion testing when a supervisor observes signs of impairment.13eCFR. 49 CFR 382.301 – Pre-Employment Testing A positive result or a refusal is treated as seriously as a DUI conviction for disqualification purposes.
Renewal and Ongoing Compliance
CDL renewal periods are set by each state, with most licenses valid for four to eight years. Your medical certificate renews on its own schedule, typically every two years, or annually if you have a qualifying medical condition.7Federal Motor Carrier Safety Administration. For How Long Is My Medical Certificate Valid? Letting the medical certificate lapse downgrades your CDL and makes your endorsements unusable until you recertify.
Most states also require a fresh background check at each S endorsement renewal, and some require periodic refresher training for school bus drivers. Requirements vary, so contact your state’s licensing agency or department of education well before your renewal date. Several states let you begin renewal 90 days early, which is worth doing because background check processing times can be unpredictable.
What to Budget
Costs add up across several line items. A DOT medical exam runs roughly $75 to $225 depending on the provider and your location. Fingerprinting and background checks typically cost $40 to $100. State CDL and endorsement testing fees generally fall between $50 and $150 for the combination of written and skills tests. ELDT training through a registered provider is often the biggest expense, though many school districts and bus companies cover training costs for drivers they plan to hire. If you’re paying out of pocket, get quotes from more than one provider on the FMCSA’s Training Provider Registry before committing.