What an S endorsement is and why you might need one
An S endorsement is a notation on your driver's license that permits you to operate a school bus. Without it, you cannot legally drive a school bus even if you hold a commercial driver's license (CDL). The endorsement signals to law enforcement and your employer that you have passed the specific training and testing required to transport students safely.
You need an S endorsement if your job involves driving a school bus for a school district, private school, or charter school. Some states also require it for driving buses that transport students to extracurricular events or field trips. If you already hold a CDL and want to add this endorsement, the process is separate from your initial CDL — you do not need to renew your entire license.
Key Takeaways
- An S endorsement requires you to pass a written test on school bus safety rules and student management, plus a skills test that includes a pre-trip inspection and on-road driving.
- You must hold a valid CDL in your state before you can add an S endorsement; the endorsement cannot stand alone.
- Most states require you to pass a Department of Transportation (DOT) medical examination specific to school bus drivers before testing.
- The written test covers passenger safety procedures, loading and unloading zones, and how to respond to emergencies on a school bus.
- After you pass both tests, you visit your state's Department of Motor Vehicles to pay the endorsement fee and have it added to your license.
Confirm you meet the baseline requirements
Before you begin, verify that you hold a valid Class B CDL (or higher) in your state. An S endorsement cannot be added to a regular passenger license — you must already have a commercial license. If you do not yet have a CDL, you will need to obtain one first through your state's standard CDL testing process.
You must also be at least 18 years old (or 21 in some states) and have a clean driving record. Most states disqualify you from an S endorsement if you have certain moving violations or criminal convictions within a set timeframe. Check your state's Department of Motor Vehicles website or call their commercial driver's license unit to confirm your specific state's age and record requirements.
Complete a DOT medical examination for school bus drivers
Your state's Department of Motor Vehicles will require you to pass a DOT medical examination performed by a certified medical examiner. This exam is more detailed than a standard CDL medical exam because school bus drivers transport children. The examiner checks your vision, hearing, blood pressure, and ability to operate the vehicle safely.
You can find a certified medical examiner through your state's DMV website or by searching the National Registry of Certified Medical Examiners. Once you pass, the examiner will issue a Medical Certificate (also called a Medical Examiner's Certificate). Bring this certificate with you when you take your S endorsement tests. The certificate is valid for two years, so if you do not pass your tests within that window, you will need a new examination.
Study for and pass the written knowledge test
The S endorsement written test covers school bus operation, student safety, and emergency procedures. Your state's DMV publishes a study guide (often called the School Bus Endorsement Manual or Commercial Driver's License Manual, S Endorsement section) that outlines every topic the test will cover. read it from your state's DMV website or pick up a printed copy at your local DMV office.
The test typically includes questions about pre-trip vehicle inspections, proper loading and unloading procedures, how to manage students on the bus, what to do if a student is injured, and how to handle mechanical failures or emergencies. The number of questions and passing score vary by state — most require 80 percent or higher. You take the test at your state's DMV office or an approved testing location. Bring your Medical Certificate, valid ID, and any required fees.
Complete the skills test, including the pre-trip inspection and road test
After you pass the written test, you must pass a skills test that has two parts: a pre-trip inspection and an on-road driving test. The pre-trip inspection requires you to walk around and under a school bus, checking lights, brakes, mirrors, emergency equipment, and other safety systems while an examiner watches and asks you questions. You must identify what each component does and spot any defects.
The on-road portion tests your ability to operate the school bus safely in real traffic. You will be asked to perform specific maneuvers such as backing up, turning, and stopping smoothly. The examiner also observes how you handle the larger vehicle, use mirrors, and follow traffic laws. The entire skills test usually takes 45 minutes to an hour. You must bring a school bus (your employer or a testing facility can provide one) and your Medical Certificate to this appointment.
Submit your endorsement request and pay the fee at the DMV
Once you have passed both the written and skills tests, visit your state's Department of Motor Vehicles in person to submit your S endorsement request. Bring your current CDL, the passing test scores (the testing location will give you documentation), your Medical Certificate, and a valid form of ID. You will also need to pay an endorsement fee, which varies by state — some charge $10 to $20, while others charge more.
The DMV will process your request and issue you a new license with the S endorsement printed on it. In most states, this happens on the spot or within a few business days. Once your license shows the S endorsement, you are legally permitted to drive a school bus. Keep your Medical Certificate with you or in a safe place, because you will need to renew it every two years to maintain your endorsement.
Maintain your S endorsement over time
Your S endorsement remains valid as long as your CDL is valid and your Medical Certificate is current. Every two years, you must renew your Medical Certificate by visiting a certified medical examiner. If your Medical Certificate expires, your S endorsement becomes invalid even if your CDL is still active, and you cannot legally drive a school bus until you pass a new medical exam.
Some states also require school bus drivers to complete refresher training or pass a new skills test when renewing their endorsement. Check with your employer or your state's DMV to learn whether your state has this requirement. If you move to a different state, you will need to transfer your CDL and S endorsement to that state's DMV — the process and requirements vary, so contact the new state's DMV before you move.
Frequently Asked Questions
Can I get an S endorsement if I have a speeding ticket or accident on my record?
It depends on how recent the violation is and how serious it was. Most states disqualify you only if the violation occurred within the past three to five years. Contact your state's DMV commercial driver's license unit with details of your record — they can tell you whether you are disqualified or whether you can proceed.
How long does it take to get an S endorsement from start to finish?
The timeline varies. If you already have a CDL and pass your medical exam, written test, and skills test on the first try, you could have your endorsement within two to four weeks. If you need to study longer, retake a test, or wait for a medical exam appointment, it may take two to three months.
Do I have to use a school bus owned by my employer for the skills test?
Most states allow you to use any school bus that meets DOT specifications. Your employer's bus is the easiest option, but some DMV offices partner with testing facilities that have buses available. Ask your state's DMV or your local testing center whether they provide a bus or whether you must bring your own.
What happens if I fail the written test or skills test?
You can retake the test. Most states allow you to retake it within a certain number of days (often 14 to 30 days) without paying the full fee again. Check your state's DMV rules on retesting fees and waiting periods before your first attempt.
Can I keep my S endorsement if I change jobs and no longer drive a school bus?
Yes. The endorsement stays on your license as long as your CDL and Medical Certificate remain valid. You do not have to use it, and you can add it back to your driving record later if you return to school bus driving. However, you must keep your Medical Certificate current if you want to maintain the endorsement.