The rules for suspended driver's licenses vary from state to state, as each state has its own regulations regarding the reasons a license can be suspended and also the length of the suspension. In Montana and Florida, a first DUI conviction results in a six-month license suspension.
Illinois has harsher punishments for a first DUI conviction, as it comes with a mandatory one-year suspension. In the state of Washington, a person's license is not suspended after their first DUI conviction. Instead, the state issues a five-year probationary license. If the person is then arrested for another DUI or major traffic violation while driving on their probationary license, their driver's license is then suspended for two years.
Florida and Montana laws both state that a person's license is to be suspended for one full year if they are convicted of a second DUI offense within five years of the first. Illinois again has much stricter laws in this area, as a second DUI offense within 20 years of the first results in a person's license being suspended for five years.
There are numerous other reasons that a driver's license can be suspended, including accumulating too many DMV points within a given time, failure to pay a fine or appear in court and inability to safely operate a motor vehicle.