Most states have a zero-tolerance (or near zero-tolerance) blood alcohol concentration (BAC) level of .02 for drivers under the legal drinking age (usually 21) that will result in a DUI/DWI charge. Some states set the BAC level at which a minor may be charged with DUI/DWI at .05. And some states will charge a minor driving a vehicle with a BAC of less than the state’s per se intoxication level (usually .08) with violating a zero-tolerance law such as driving while ability impaired (DWAI)—but will charge a minor with a BAC of .08 or more with per se (pronounced purr-say) DUI/DWI based on the state’s BAC-level definition of intoxication—or, in the absence of a chemical test of blood, breath, or urine, will charge the minor with common law DUI/DWI based on the police officer’s belief the minor was driving while intoxicated.

DUI/DWI criminal offenses, punishments, and terms used for underage DUI/DWI vary from state to state. These laws are generally located in a state’s statutes—often in the penal code or criminal code.

In Pennsylvania, the state enforces a zero-tolerance policy for underage drinking and driving. Drivers under the age of 21 are subject to a much lower blood alcohol concentration (BAC) limit than the standard .08% for those of legal drinking age. In Pennsylvania, the BAC limit for drivers under 21 is .02%. If an underage driver is found to have a BAC of .02% or higher, they can be charged with Driving Under the Influence (DUI). The penalties for underage DUI can include fines, license suspension, and even jail time, depending on the circumstances and whether it is a first or repeat offense. The state may also impose additional charges if the BAC is .08% or higher, consistent with the standard DUI charges for of-age drivers. It's important for minors to understand that any amount of alcohol in their system can lead to serious legal consequences under Pennsylvania's zero-tolerance law.