[header] How to get a commercial drivers license (cdl ) [title] Check your state's eligibility requirements. [step] Each state has its own age, residency, and medical requirements for licensed commercial drivers. Generally, you must be at least 18 years old, or 21 years old if you plan to drive across state lines. 
[substeps] Even if you never drive across state lines, you may need to be 21 if you work for a transportation or trucking company that is involved in interstate commerce. Some states require you to have been a resident of the state for several months before you are eligible to apply for a cdl.