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 Iowa, the state enforces a zero-tolerance policy for underage drinking and driving. This means that any driver under the age of 21 who is found to have a blood alcohol concentration (BAC) of .02 or higher can be charged with Operating While Intoxicated (OWI), which is the equivalent of DUI/DWI in other states. Iowa's approach aligns with the federal push to discourage underage drinking and driving. If an underage driver is found with a BAC of .08 or higher, they can be charged with the standard OWI offense, just like drivers of legal drinking age. The penalties for underage OWI can include fines, license suspension, and even jail time, depending on the circumstances and whether it is a first or subsequent offense. It's important to note that these laws are subject to change, and an attorney can provide the most current legal advice regarding underage OWI offenses in Iowa.