Class B CDL basics and what it covers

A Class B commercial driver's license lets you operate single vehicles weighing 26,001 pounds or more, but not combination vehicles (a tractor pulling a trailer). You can also drive any vehicle that a Class C driver can operate. The key difference from a Class A CDL is that Class B does not permit you to haul trailers, which keeps your licensing requirements and testing scope narrower.

Common vehicles you can drive with a Class B CDL include straight trucks (dump trucks, box trucks, delivery trucks), city buses, school buses, and motor homes over 26,001 pounds. If your job involves pulling a trailer of any size, you need a Class A instead. If you drive a single vehicle under 26,001 pounds, you do not need a CDL at all.

Key Takeaways

  • You must be at least 18 years old to hold a Class B CDL, though some states require 21 for interstate driving.
  • A valid regular driver's license and a medical certificate from a Department of Transportation-certified examiner are required before you test.
  • You will take a written knowledge test, a pre-trip vehicle inspection test, and a behind-the-wheel driving test specific to Class B vehicles.
  • Most states require you to hold a Class B commercial learner's permit for at least 14 days before you can take the driving test.
  • Endorsements like air brakes, passenger, or hazmat are added to your Class B CDL based on the type of vehicle or cargo you handle.

Age and residency requirements

You must be at least 18 years old to obtain a Class B CDL in all states. However, if you plan to drive across state lines (interstate commerce), many states require you to be 21. Some states allow 18-year-olds to drive intrastate only — meaning within that state's borders — until they turn 21. Check your state's Department of Motor Vehicles website to confirm the age rule that applies to your situation.

You must also be a resident of the state where you are obtaining the license, or have established residency there. Most states require proof of residency such as a utility bill, lease agreement, or bank statement dated within the last 60 days. If you are relocating for work, you may need to establish residency before you can test.

Medical certificate and vision requirements

Before you take any CDL test, you must obtain a Department of Transportation medical certificate from a certified medical examiner. This is not your regular doctor's checkup — it must come from an examiner on the National Registry of Certified Medical Examiners. The examiner checks your vision, hearing, blood pressure, and general health to confirm you can safely operate a commercial vehicle.

Vision must be at least 20/40 in each eye, with or without correction, and you must have at least 70 degrees of vision in each eye. If you have had eye surgery or wear corrective lenses, bring documentation. The medical certificate is valid for two years. You will need to renew it before it expires if you want to keep your CDL active.

Knowledge test and written exam topics

The Class B CDL knowledge test covers vehicle operation, safety, and road rules specific to large trucks and buses. You will answer 50 multiple-choice questions, and you must score at least 80 percent to pass. The test is administered at your state's Department of Motor Vehicles office and usually takes 30 to 45 minutes.

The test covers braking systems (including air brakes), vehicle inspection, load securement, hazardous materials basics, passenger safety if you are driving a bus, and emergency procedures. You can study using your state's CDL manual, which is free and available online or at the DMV. Many people also use practice tests to prepare. You typically have three attempts to pass; if you fail all three, you must wait a set period (often 7 days) before retesting.

Pre-trip inspection and skills tests

After you pass the knowledge test, you take a pre-trip vehicle inspection test. An examiner asks you to walk around and point out key components of a Class B vehicle — lights, mirrors, tires, brakes, coupling devices (if applicable), and safety equipment. You must explain what you are checking and why. This test has no written portion; the examiner listens to your explanation and scores based on accuracy and completeness.

You will also take a behind-the-wheel driving test in an actual Class B vehicle. The test usually lasts 30 to 45 minutes and includes basic vehicle control (backing, turning, parking), driving on public roads, and emergency maneuvers. The examiner scores you on smooth operation, proper use of mirrors, lane control, and safe decision-making. You must pass all three components — knowledge, pre-trip, and driving — to receive your Class B CDL.

Commercial learner's permit and waiting period

Most states require you to hold a Class B commercial learner's permit for a minimum of 14 days before you can take the behind-the-wheel test. You obtain this permit by passing the knowledge test and providing your medical certificate. During this waiting period, you can practice driving a Class B vehicle, but only with a licensed CDL holder in the passenger seat.

Some states allow you to waive part of the waiting period if you have prior commercial driving experience or military training. Check your state's rules before you schedule your test. If you take the driving test before the waiting period is complete, you will be turned away and may lose your test fee.

Endorsements and restrictions

Your Class B CDL may include endorsements — special permissions to operate certain vehicle types or carry certain cargo. Common endorsements are P (passenger vehicles like buses), N (tank vehicles), H (hazardous materials), and X (combination of tank and hazmat). You obtain endorsements by passing additional written tests beyond the base Class B exam.

You may also have restrictions placed on your license if you do not meet certain standards. For example, if you wear corrective lenses, you may have a vision restriction. If you have an automatic transmission vehicle during your driving test, you may be restricted to automatic transmission only. Restrictions limit where and how you can drive, so ask the examiner what restrictions explore to you before you leave the DMV.

Frequently Asked Questions

Can I get a Class B CDL if I have had a DUI or traffic violations?

A DUI or serious traffic violation does not automatically disqualify you, but it may delay your process or result in restrictions. Each state has different rules about what violations bar you from getting a CDL. Contact your state's Department of Motor Vehicles to find out whether your record affects your may be able to access.

What is the difference between a Class B and Class A CDL?

A Class A CDL allows you to drive combination vehicles (tractor and trailer), while a Class B does not. Class A requires more extensive testing because combination vehicles are more complex to operate. If you only need to drive a single large vehicle, Class B is sufficient and faster to obtain.

How long does it take to get a Class B CDL from start to finish?

The timeline depends on your state and how quickly you prepare. The mandatory waiting period is at least 14 days after you pass the knowledge test. Add time for studying, scheduling your tests, and any retakes if needed. Most people complete the process in 4 to 8 weeks.

Do I need a Class B CDL to drive a school bus?

Yes, you need a Class B CDL with a passenger (P) endorsement to drive a school bus. You must pass the base Class B tests plus an additional written test for the P endorsement. Some states also require fingerprinting and a background check for school bus drivers.

What happens if I fail the behind-the-wheel test?

You can retake the test, but you must wait a set period — usually 7 to 14 days depending on your state — before scheduling another attempt. You keep your commercial learner's permit and can continue practicing. There is typically a fee each time you retake the test.