Maryland CDL Endorsements
Endorsements are add-ons to your Maryland CDL that authorize specific vehicle types or cargo. Each requires a separate knowledge test, taken through Maryland Motor Vehicle Administration, and the endorsement codes are federal, so a Maryland endorsement is recognized in every state. With port and container freight, government and defense logistics, food distribution shaping Maryland freight, the examples under each endorsement show where that endorsement pays off locally.
Not all endorsements apply to every CDL class. Use the CDL Selector to find what you need.
When It's Required in Maryland
In Maryland (MD), required to transport any quantity of hazardous materials that require placarding under federal HazMat regulations.
What to Study for the MD Test
For the Maryland (MD) Hazardous Materials test, study shipping papers, placard and label selection, safe loading and segregation, emergency response procedures, and security-awareness requirements under federal law.
Hazardous Materials in Maryland (MD)
- Port and container freight: placarded containers and ISO tanks coming through the ports
- Government and defense logistics: ammunition and defense cargo under placards for contractors
- Food distribution: cleaning agents, batteries, and other placarded retail freight
- Pharmaceutical supply: chemical and pharmaceutical shipments that require placards
When It's Required in Maryland
In Maryland (MD), required for vehicles designed to transport liquids or gases in a tank permanently or temporarily attached to the vehicle, with individual tank capacity of more than 119 gallons.
What to Study for the MD Test
For the Maryland (MD) Tank Vehicles test, study liquid surge and baffled tanks, outage allowances, inspections, high-center-of-gravity handling, and rollover prevention strategies.
Tank Vehicles in Maryland (MD)
- Port and container freight: ISO tank containers of chemicals and food-grade liquids
- Food distribution: beverage, dairy, and food-grade liquid tankers
- Pharmaceutical supply: bulk chemical tankers between plants
When It's Required in Maryland
In Maryland (MD), required for commercial vehicles designed to carry 16 or more passengers including the driver: charter buses, transit coaches, and similar vehicles.
What to Study for the MD Test
For the Maryland (MD) Passenger test, study passenger safety protocols, controlled loading and unloading, emergency door operation, on-road passenger management, and distracted-driving rules.
Passenger in Maryland (MD)
- Government and defense logistics: troop and agency passenger transport
- Transit agencies, charter companies, and church or community buses across Maryland
When It's Required in Maryland
In Maryland (MD), required for any driver transporting school-age students in a vehicle classified as a school bus under federal or state law.
What to Study for the MD Test
For the Maryland (MD) School Bus test, study student loading zones, stop-signal arm procedures, railroad crossing rules, mirror adjustment, emergency evacuation drills, and state-specific school bus regulations.
School Bus in Maryland (MD)
- Maryland school districts and their contractors: every route driver needs S plus P
- Activity and athletics trips, which use the same S-endorsed drivers
When It's Required in Maryland
In Maryland (MD), required to pull double or triple trailers where permitted by state law. Common in regional and long-haul freight operations.
What to Study for the MD Test
For the Maryland (MD) Doubles & Triples test, study coupling and uncoupling double and triple combinations, pull-out stability, off-tracking behavior, full combination inspections, and safe following distance.
Doubles & Triples in Maryland (MD)
- Port and container freight: twin-trailer LTL sets running the port and rail corridors
- Food distribution: twin 28-foot LTL trailer sets on the interstates
When It's Required in Maryland
In Maryland (MD), required for any vehicle equipped with an air brake system, which covers most Class A tractor-trailers and many Class B straight trucks.
What to Study for the MD Test
For the Maryland (MD) Air Brakes test, study air brake components, dual-circuit systems, inspection procedures, warning devices, pressure gauges, and stopping distance at highway speeds.
Air Brakes in Maryland (MD)
- Almost every Class A and Class B vehicle in Maryland; skip this test and your CDL carries an L restriction
When It's Required in Maryland
In Maryland (MD), essential for Class A drivers operating tractor-trailers, lowboys, and other multi-unit combinations over federal weight thresholds.
What to Study for the MD Test
For the Maryland (MD) Combination Vehicles test, study coupling and uncoupling procedures, air line connections, trailer handling characteristics, off-tracking, and full combination vehicle inspections.
Combination Vehicles in Maryland (MD)
- Port and container freight: container drayage between the ports, rail ramps, and warehouses
- Government and defense logistics: defense logistics loads on and off base
- Food distribution: regional and over-the-road tractor-trailer distribution runs
- Required for any Class A CDL issued in Maryland
Not sure which Maryland CDL endorsements you need?
Answer a few questions about your vehicle and operation, and the Maryland CDL Selector Tool pinpoints the endorsements you need in Maryland.