In states, the minimum age to obtain a driver's license varies from 14 years, 3 months in South Dakota to as high as 17 in New Jersey. In most states, a graduated licensing law applies to newly licensed teenage drivers, going by names such as "Provisional Driver", "Junior Operator", "Probationary Driver" or "Intermediate License." These licenses restrict certain driving privileges, normally whether the new driver may carry passengers and if so how many, as well as setting a curfew for young drivers to be off the roads. Unlike in Australia and some provinces of Canada, however, graduated licensing laws do not require lowered speed limits, displaying of L and P plates, restrictions on towing a trailer or boat, or prohibitions on highway driving or operating high performance cars. GDLs are subject to the same 50 state reciprocity that unrestricted licenses are, with the exception that drivers under 16 may not be permitted to operate in states with higher licensing ages. Graduated license holders must always adhere to the restrictions of their home state regardless of where they are driving. Additionally, depending on local laws, underage drivers may also be subject to the GDL laws of the state they are driving in as well, although this is not always the case.
In addition to the above restrictions, drivers under 18 are usually required to attend a comprehensive Driver's education program either at their high school or a professional driving school and take a certain number of behind the wheel lessons with a certified driving instructor before applying for a license. Some states like New York also require new adult drivers to attend some form of driver's education before applying for a license.
Unlike in Europe and Australia, drivers who are 18 or older (21 in New Jersey and the District of Columbia) when they first become licensed are not subject to the restrictions . However, in some states all newly licensed adult drivers may be on probation for a set amount of time (usually between six months and two years), during which traffic violations carry harsher penalties or mandatory suspensions that would not normally apply to experienced drivers.
According to federal law, the minimum age to operate a commercial vehicle in interstate transit (i.e. across state lines) is 21, and as a result the minimum age to apply for an unrestricted commercial driver's license is 21. Driving a school bus also requires a CDL, however the minimum age to drive a school bus is typically higher, usually 25. Some states issue restricted intrastate commercial driver's licenses, valid for operating commercial vehicles in that state only, to drivers aged 18 and older. Professional drivers who are aged 18–20 typically cannot be licensed to drive tractor trailers, hazardous materials, or school buses.