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 Utah, the state enforces a zero-tolerance policy for underage drinking and driving. This means that any detectable amount of alcohol in the system of a driver under the age of 21 can result in a DUI charge. Specifically, Utah's BAC limit for drivers under the legal drinking age is .02, which is lower than the standard .08 BAC limit for drivers 21 and over. If an underage driver is found to have a BAC of .02 or higher, they can be charged with DUI. For those with a BAC of .08 or higher, the charge would be the same as for adults, which is per se DUI, based on the state's definition of intoxication. Additionally, if there is no chemical test available, an officer's observation of impairment can lead to a DUI charge under common law. The penalties for underage DUI/DWI can include fines, license suspension, and mandatory educational programs, among others, and are detailed in Utah's statutes within the traffic code.