Class A
The combination license.
- One run
- 50 questions
- To pass
- 40 of 50
Washington DC runs its commercial license through the District of Columbia Department of Motor Vehicles, the same agency that issues a car license, rather than through a State Police detachment or a separate motor vehicle safety board. DC is not a state, and the DMV's operation reflects that: it administers driving for one compact jurisdiction rather than a scattered network of counties, so getting to a service center to sit the knowledge exam is rarely the long drive it can be elsewhere.
Every figure below names the document it came from, so you can check it rather than take our word for it.
Fees change without notice, so we do not repeat them here. Check District of Columbia Department of Motor Vehicles for the current cost.
The knowledge tests are set by federal rule, so the questions are the same wherever you sit them. What changes is the paperwork above.
The combination license.
The heavy straight vehicle license. Group B covers a single vehicle rating 26,001 pounds or more, or one towing a unit of 10,000 pounds or less.
The small vehicle license.
The knowledge test every commercial driver takes, whatever class or endorsement they are after.
Required before you may drive any commercial vehicle with air brakes.
Required for a Class A license. Coupling and uncoupling, off-tracking, trailer brakes and the handling of a vehicle that is jointed in the middle.
The H endorsement. Placarding, shipping papers, loading and segregation rules, and what to do when something leaks.
The N endorsement. Surge, baffles, bulkheads, high center of gravity and the way a part-full tank changes how a vehicle stops and turns.
The T endorsement. Coupling and uncoupling multiple trailers, converter dollies, crack-the-whip and the inspection points a second trailer adds.
The P endorsement. Pre-trip and post-trip checks on a bus, loading and unloading, standee lines, and handling passengers on the road.
The S endorsement, taken alongside the passenger endorsement. Danger zones, mirror adjustment, loading and unloading students, and railroad crossings.
A study drill for the pre-trip inspection.
Most of what is tested comes from federal rule, not from DC itself. The knowledge exams, the endorsements you can add, and the pass mark are set out in 49 CFR Part 383 and read the same everywhere. What is different about DC is geography rather than paperwork: the District borders Maryland and Virginia on every side, so a commercial driver licensed here is often working across a state line within the same shift, sometimes within the same delivery run. That makes the federal age rule for interstate driving — 21, rather than the 18 that covers driving within DC alone — a live distinction for DC drivers in a way it is not for someone whose whole route stays inside one large state.
Everyone starts with general knowledge. Beyond that, what you add depends on the vehicle. Air brakes need their own exam, and skipping it does not block a license — it adds an air brake restriction that rules out driving anything fitted with them. A combination vehicle, meaning a trailer over ten thousand pounds, needs the combination exam. Then the endorsements: tank vehicles, doubles and triples, hazardous materials, passenger, school bus. Hazardous materials carries an extra step everywhere in the country — a Transportation Security Administration background check that runs alongside the written exam and on its own timeline, so it is worth starting early rather than leaving until the rest of the paperwork is done.
You need a commercial learner permit before the skills test, and federal rule sets a minimum wait of fourteen days between getting the permit and sitting that test. Because DC DMV's service centers are close together, the practical constraint on drivers here tends to be scheduling an appointment rather than traveling to one, so book early and use the wait productively — sit the knowledge exams as soon as the permit is issued rather than near the end of the window, so a resit still fits inside it.
Fees are not listed on this site. DC DMV sets and changes them, and a stale number sends you on a wasted trip, so check with the DMV directly before you go. What this site covers is which questions the exams draw from, and where in the source material each answer comes from.
Every question on every one of these is free, and each answer names the handbook page it came from.
Every question names the handbook, section and page it was read from, so you can check the answer instead of taking our word for it.
How we write these