As you probably know, it is illegal to drink alcohol until you reach 21 years of age. Yet many underage individuals still drink and drive. As a result, the State of Illinois provides very severe penalties for someone charged with an underage DUI.
Generally, in Illinois, someone under the age of 21 can be arrested for drunk driving if they have any amount of alcohol in their system, provides the Illinois Secretary of State. So if your blood alcohol level is above 0.00 percent, you can be charged with a DUI.
Illinois law is very harsh and unlike many states that only make it a crime if you have a blood alcohol level above some minimal amount like 0.02, it is a crime in Illinois for an underage individual to even have a sip of alcohol and drive.