Licensing and Medical Requirements

Commercial Driver License Classes

A Commercial Driver License (CDL) is required to operate heavy, large, or hazardous commercial motor vehicles. Specifically, you need a CDL if you operate a single vehicle with a Gross Vehicle Weight Rating (GVWR) of 26,001 pounds or more. You also need one if you drive a combination vehicle with a Gross Combination Weight Rating (GCWR) of 26,001 pounds or more, provided the vehicle being towed has a GVWR exceeding 10,000 pounds. Finally, a CDL is mandatory for any vehicle designed to transport 16 or more passengers (including the driver), or any size vehicle carrying hazardous materials requiring placards or carrying select agents or toxins listed in 42 CFR part 73.

Federal CDL Classes A, B, and C depend on vehicle configuration and weight ratings; Class C also depends on passenger capacity or hazardous cargo. A Class A license covers combination vehicles with a GCWR of 26,001 pounds or more, provided the towed unit has a GVWR of more than 10,000 pounds. A driver qualified for Class A may also legally operate Class B and Class C vehicles. Class B covers a single vehicle with a GVWR of 26,001 pounds or more, including such a vehicle towing another vehicle with a GVWR not exceeding 10,000 pounds. Holding a Class B license permits you to operate Class C vehicles as well.

A Class C license covers single vehicles with a GVWR under 26,001 pounds, or such vehicles towing another vehicle not exceeding 10,000 pounds GVWR, that meet special conditions. These conditions are: requiring hazardous materials placards, transporting select agents or toxins, or being designed to transport 16 or more passengers including the driver. Additionally, individual states may choose to go beyond federal standards by requiring a CDL for buses designed to carry fewer than 16 passengers.

Endorsements and Operational Restrictions

Endorsements grant special permission to operate specialized types of commercial equipment, while restrictions place specific limits on your operating privileges. You must pass specialized exams to earn endorsements. If you hold a Commercial Learner’s Permit (CLP), federal regulations allow only three endorsements to be added: Passenger (P), School bus (S), and Tank vehicle (N). The Double and Triple Trailers (T) endorsement requires a specialized knowledge exam and allows Class A drivers to pull multiple trailers. The Hazardous Materials (H) endorsement requires a specialized written examination and a Transportation Security Administration (TSA) background check, which includes fingerprinting mandated by the Department of Homeland Security.

The Tank Vehicle (N) endorsement applies to Class A or B vehicles designed to transport liquids or gases in permanently or temporarily attached tanks. The individual tank capacity must be more than 119 gallons, and the total aggregate capacity must be 1,000 gallons or more. For Class C vehicles, the N endorsement applies only when hauling hazardous materials. Drivers of tank vehicles hauling hazardous materials or waste in amounts requiring placards must obtain the combined X endorsement by passing the tank vehicle and hazardous materials knowledge tests. Passenger (P) and School Bus (S) endorsements each require a specialized knowledge examination and passing skills tests in a passenger vehicle or school bus, respectively.

Restrictions limit driving privileges for reasons that may include the vehicle or equipment used for a skills test, medical status, or intrastate-only certification. CLP holders face explicit safety limits: a CLP with a P or S endorsement includes Restriction P, prohibiting carrying passengers other than specified auditors, inspectors, examiners, other trainees, and the accompanying CDL holder. A CLP with an N endorsement carries Restriction X, which prohibits cargo and allows operating only an empty tank vehicle that has been purged of hazardous residue. General restrictions also reflect testing equipment: testing with an automatic transmission (defined as any transmission not operating fully on a manual gear shift and clutch principle) adds Restriction E (no manual transmission). Restriction L applies if you do not take or fail the air brakes knowledge-test component, or take the skills test in a vehicle without air brakes; taking the skills test in a vehicle with air-over-hydraulic brakes results in Restriction Z.

Other restrictions include Restriction K, which limits the driver to intrastate commerce only. Restriction O prohibits operating a Class A tractor-trailer connected by a fifth wheel if you took the Class A skills test in a combination with a non-fifth-wheel connection, or in a fifth-wheel-equipped combination that was not a truck-tractor/semitrailer. Passenger restrictions also apply based on testing equipment: testing in a Group B passenger vehicle results in Restriction M (no Class A passenger vehicles), and testing in a Group C passenger vehicle triggers Restriction N (no Class A or B passenger vehicles). Restriction V indicates that a medical variance has been recorded for the driver.

Medical Certification and Self-Certification Rules

When applying for a CDL permit or renewing, upgrading, adding endorsements to, or transferring a CDL, drivers must provide their SDLA with information about the type of CMV operation they drive or expect to drive. This process is known as self-certification. Interstate commerce includes trips crossing a state or national border and trips within one state when the cargo or passengers are part of a trip that began or will end outside that state; otherwise, CMV operation entirely within one state is intrastate commerce. If you operate in both interstate and intrastate commerce, you must select interstate commerce.

Interstate commerce is further divided into excepted and non-excepted categories. Non-excepted interstate drivers must meet federal physical qualification standards and submit a current medical examiner's certificate to their SDLA. If you operate in non-excepted interstate commerce and fail to keep your medical certificate current, you become not-certified and risk losing your commercial driving privileges. If the state is notified that you have been issued a medical variance, it must record that variance using Restriction V on your CDL, if issued, and in your CDLIS driver record.

You operate in excepted interstate commerce only when your commercial driving involves specific exempt activities listed in the manual. These include transporting school children or staff between home and school, operating as a government employee, driving fire or rescue equipment during emergencies, working in custom harvesting, or transporting bees seasonally. If you operate in both excepted and non-excepted interstate commerce, you must certify as non-excepted and maintain an active medical examiner's certificate.

The Three-Part Skills Test and Operational Recordkeeping

After passing the required knowledge tests, you can take the CDL skills test when you are eligible. The test consists of three segments that must be taken in a mandatory, step-by-step order: the vehicle inspection, basic vehicle control, and on-road driving. You must pass each individual segment before you are allowed to advance to the next one. During the vehicle inspection test, you must point to or touch and name every item being inspected, explaining clearly what you are checking and why. A vehicle with components marked or labeled cannot be used for the CDL skills test.

A CDL-required vehicle operated in interstate commerce must, with few exceptions, be registered under IRP and IFTA; whether IRP plates and an IFTA license are required depends on each program’s qualified-vehicle definitions. These programs cover operations across the 48 contiguous United States and 10 Canadian provinces. With the exceptions noted in the manual, an IRP-qualified power unit is used or intended for use in two or more member jurisdictions to carry passengers for hire or primarily to transport property, and meets one of these conditions: it has two axles and a gross or registered gross vehicle weight over 26,000 pounds; it has three or more axles; or it is used in a combination whose gross vehicle weight exceeds 26,000 pounds. Under the excerpt's IFTA definition, a vehicle used, designed, or maintained to transport persons or property qualifies if it has two axles and a gross or registered gross vehicle weight over 26,000 pounds, or is used in a combination whose gross or registered gross vehicle weight exceeds 26,000 pounds; recreational vehicles are excluded. IFTA simplifies accounting by allowing a motor carrier to file just one quarterly fuel tax return with its base jurisdiction.

If the vehicle is registered under IRP and the motor carrier is licensed under IFTA, mandatory distance and fuel recordkeeping applies; the manual describes the IVDR as a way to capture that information. An IVDR records all distance traveled and fuel purchased. The distance record must show trip dates, origin and destination, routes traveled, beginning and ending odometer or hubometer readings, total trip distance, jurisdiction-by-jurisdiction distance, and the vehicle identifier. Drivers must record an odometer reading at the start of the day, whenever crossing a state or provincial border, and at the end of the trip or day. An acceptable fuel receipt or invoice must show the purchase date, seller's name and address, quantity purchased, fuel type, price per gallon or liter or total sale amount, unit number or other unique vehicle identifier, and purchaser's name. Original IVDR records must be maintained for at least four years.