What a Class B License Lets You Drive
A Class B commercial driver's license authorizes you to operate single vehicles weighing 26,001 pounds or more, or any vehicle in that weight class towing a trailer under 10,000 pounds. The most common Class B vehicles are straight trucks — dump trucks, box trucks, delivery trucks, and cement mixers. You cannot drive a tractor-trailer combination (which requires a Class A license) or a bus carrying passengers (which requires a Class B with a passenger endorsement).
Class B is the middle tier of commercial licensing. It sits between Class C (regular driver's license) and Class A (tractor-trailers). If your job involves hauling freight in a single large truck but not pulling a trailer, or if you drive a city bus or school bus, a Class B is what you need.
Every state issues Class B licenses, but the written test content, road test requirements, and medical certification rules vary slightly by state. The process typically takes four to eight weeks from start to finish, depending on how quickly you schedule your tests and whether you pass on your first attempt.
Key Takeaways
- You must hold a valid Class C driver's license and pass a Department of Transportation medical exam before you can test for a Class B.
- The written test covers vehicle inspection, safe driving practices, and cargo handling — study materials are available from your state's DMV website.
- The road test is conducted in an actual Class B vehicle and lasts 30 to 45 minutes; you must demonstrate basic vehicle control, backing, and highway driving.
- You will need to provide proof of identity, residency, Social Security number, and medical certification at the time of your written test.
- Some states allow you to take the written test before your medical exam is complete, but you cannot take the road test until the medical certificate is on file.
Step 1: Get Your DOT Medical Certificate
Before you can sit for any commercial driver's license test, you must obtain a Department of Transportation (DOT) medical certificate. This is not optional — your state's DMV will not let you test without it. The exam is performed by a certified medical examiner (usually a doctor, nurse practitioner, or physician assistant) and takes about 30 minutes.
The examiner checks your vision, hearing, blood pressure, and medical history. They will ask about any medications you take, whether you have diabetes or heart conditions, and whether you have ever been denied a medical certificate before. The certificate is valid for two years from the date of the exam. You can find a certified examiner through your state's DMV website or by searching the National Registry of Certified Medical Examiners at fmcsa.dot.gov.
The cost varies by state and examiner, typically between $75 and $150. Some employers cover this cost; ask before you pay out of pocket. Once you have the certificate, bring the original to your DMV when you take your written test.
Step 2: Study for and Pass the Written Test
The Class B written test covers three main areas: vehicle inspection, safe driving practices, and cargo handling. The test is usually 50 questions, and you must score at least 80 percent to pass. Most states allow you to retake the test the same day if you fail, though some require a waiting period of a few days.
Your state's DMV publishes a free study guide (sometimes called the Commercial Driver's License Manual) on its website. Read it cover to cover — the test pulls directly from this material. Pay special attention to sections on pre-trip inspection (you will need to know how to inspect brakes, tires, lights, and coupling devices), hazard perception, and weight and balance. Many states also offer practice tests online for free.
Schedule your written test at your local DMV office. Bring your medical certificate, proof of identity (passport or state ID), proof of residency (utility bill or lease), and your Social Security number. Some states require you to bring your current driver's license as well. The test itself takes 30 to 45 minutes.
Step 3: Schedule and Pass the Road Test
Once you pass the written test, you can schedule your road test. This test must be conducted in an actual Class B vehicle — you cannot use a car or a smaller truck. If you do not own or have access to a Class B vehicle, some driving schools rent them for the purpose of testing, though this adds cost (typically $200 to $400 for the rental plus instruction).
The road test lasts 30 to 45 minutes and is administered by a state examiner. You will be asked to perform a pre-trip inspection (pointing out and explaining key safety components), basic vehicle control maneuvers (such as backing in a straight line or at an angle), and highway driving. The examiner is looking for smooth steering, proper use of mirrors, safe speed control, and awareness of other traffic. You must follow all traffic laws and demonstrate that you can handle the vehicle safely.
Schedule your road test as soon as you pass the written exam. Some states have long waiting lists, especially in busy urban areas. Bring your medical certificate, proof of identity, and your current driver's license. You will also need to bring the Class B vehicle you will be driving, with proof of insurance and registration.
Documents You Will Need at Each Stage
| Stage | Documents Required |
|---|---|
| Medical Exam | Photo ID, proof of residency, Social Security number (or ITIN) |
| Written Test | Medical certificate, photo ID, proof of residency, Social Security number, current driver's license |
| Road Test | Medical certificate, photo ID, current driver's license, Class B vehicle with insurance and registration |
| License Issuance | Proof of passing road test (examiner provides this), photo ID, current driver's license |
What Happens After You Pass the Road Test
After you pass the road test, the examiner will give you a document confirming your pass. Take this to your DMV office along with your photo ID and current driver's license. The DMV will issue your Class B commercial driver's license on the spot or mail it to you within one to two weeks, depending on your state's process.
Your new Class B license will show your vehicle class, any endorsements you have earned (such as a passenger endorsement or hazmat endorsement), and any restrictions (such as "not valid for passenger transport" if you did not test for that endorsement). The license is valid for four or five years, depending on your state, and you will need to renew it before it expires.
Keep your medical certificate with you or in a safe place at home. You will need to show it when you renew your license, and some employers ask to see it during hiring. If your medical certificate expires before your license does, you cannot legally drive a commercial vehicle until you renew it.
Common Reasons People Fail the Road Test
The most frequent failures happen during the pre-trip inspection, when test-takers forget to check or incorrectly describe key components like brake condition, tire tread depth, or coupling devices. Spend time learning the inspection checklist before test day — this is the easiest part to prepare for and the most common place to lose points.
Backing maneuvers are the second major failure point. Practice backing in a straight line and at an angle until you can do it smoothly without hitting cones or curbs. Many driving schools offer backing practice in their rental vehicles, and this practice is worth the cost.
On-road failures usually stem from mirror checks (examiners want to see you check mirrors frequently), speed control (going too fast or too slow for conditions), or failure to signal lane changes. These are habits you build through practice, not things you can cram the night before.
Frequently Asked Questions
Do I need a Class B license if I drive a box truck for delivery?
Only if the box truck weighs more than 26,000 pounds. Check the vehicle's gross vehicle weight rating (GVWR) on the driver's door jamb or in the owner's manual. Many delivery box trucks fall below this threshold and can be driven with a regular Class C license. If you are unsure, ask your employer or check the vehicle's documentation.
Can I take the written test before my medical exam is finished?
This varies by state. Some states allow you to take the written test and hold a passing score while your medical exam is pending, but you cannot take the road test until the medical certificate is on file with the DMV. Check with your state's DMV to confirm their policy before scheduling.
What if I fail the road test?
You can retake it, usually within a few days or weeks depending on your state's scheduling. There is no limit to how many times you can test, but each attempt costs a fee (typically $50 to $100). Most people pass on the second or third attempt after additional practice. Your medical certificate remains valid during retakes.
Do I need a Class B license to drive a school bus?
Yes, you need a Class B with a school bus endorsement (sometimes called an S endorsement). This requires an additional written test beyond the standard Class B test. The school bus test covers student safety, evacuation procedures, and passenger management. Many school districts provide study materials and cover the testing costs for new hires.
How long is a Class B license valid?
Most states issue Class B licenses valid for four or five years. Your license will show the expiration date on the front. You must renew before it expires, and you will need a current medical certificate to renew. Some states allow online renewal if there have been no changes to your information.