If you're looking into driving big rigs, then yes, you will need a Class A CDL. However, If you're looking into general driving, or if you are just curious about the requirements for a CDL-A, this guide will outline the basic requirements. I will not guarantee this is accurate in all states, or that the exact methods will apply. If you need very specific information, the best source will be the DMV/OMV in your area.
Otherwise, Here Are The General Requirements:
You need a CDL if you operate any of the following vehicles.
• All single vehicles with a manufacturer's weight rating of 26,001 pounds or more
• All trailers with a manufacturer's weight rating of 10,001 pounds or more, if the gross weight rating of the combined vehicle(s) is 26,001 pounds or more
• All vehicles designed to transport 16 or more persons (including the driver). (Private, church, buses.)
• All vehicles that carry placarded amounts of hazardous materials (see following section on exemptions).
Occasional drivers are also required to apply for a CDL and all appropriate endorsements. (e.g. Mechanics or truck sales people who test drive on a public roadway.)
A higher class CDL allows you to drive vehicles in any of the lower classes provided you have the correct endorsements.
In Certain cases, Drivers will be required to get endorsements on their license. In order to haul Tankers, Hazardous Materials, Doubles and Triples. Endorsements are also required if you operate a vehicle that has Air Brakes or is a Combination Vehicle (e.g. Tractor and Trailer) On the split side, drivers will also need endorsements to drive school buses, regular buses that have over 16 people.
Drivers that Hold a CDL will also be required to get a DOT medical Card.
To Get a medical card, it will consist of DOT approved physical. The physical accesses your overall health, such as blood pressure, and will make sure you are in good enough shape to perform the necessary duties of driving/maintaining a commercial vehicle. They will check such factors as:
Blood Pressure (For Overall Health)
Ability to Raise and Lower a Trailer (Test your ability to turn a wheel to simulate turning landing gear)
Crawl on Your Knees (This is to simulate crawling under the trailer, or looking under the tractor)
Step Up and Down Down (This is to simulate getting in and out of the truck)
There are more basic steps, for the complete list, refer to the Federal Motor Carrier Safety Administrations Web Site.
Drivers will also have to be able to perform basic driving maneuvers in a Commercial Vehicle. This will include backing (Usually, Driver and Passenger Parallel, Straight Back, Alley Dock, 45° and 90°) Basic shifting, and operating the truck in a safe manor, along with Performing a Pre-Trip Inspection which will include the ability to perform an Air Brake Check.