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 Texas, 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 (Driving Under the Influence) or DWI (Driving While Intoxicated) charge. Specifically, Texas sets the BAC (Blood Alcohol Concentration) level at .02 for drivers under the legal drinking age, which is lower than the standard .08 BAC level for drivers 21 and over. If a minor is found operating a vehicle with a BAC of .08 or higher, they can be charged with the standard DWI offense, which is the same charge an adult would face under similar circumstances. The penalties for underage DUI/DWI can include fines, license suspension, and mandatory alcohol education programs. It's important to note that even in the absence of a chemical test, a minor can still be charged based on an officer's assessment that the minor was driving while intoxicated.