California’s Zero-Tolerance DUI Laws for Underage Drivers

Last updated: February 2026

Under Vehicle Code 23136, California enforces a zero-tolerance policy that makes it illegal for anyone under 21 to drive with a blood alcohol concentration (BAC) of 0.01% or higher. This is a civil offense—not a criminal charge—but it carries an automatic one-year license suspension.

A single drink can put a driver under 21 over California’s legal limit. That is the reality of the state’s zero-tolerance framework, which sets a BAC threshold so low that even trace amounts of alcohol from cough syrup, mouthwash, or certain medications can trigger a violation. The law does not require proof of impairment. If any measurable alcohol is detected, the consequences begin immediately.

California’s approach to underage DUI is structured across three separate Vehicle Code sections, each applying at a different BAC level and carrying different penalties. Understanding which law applies—and how to challenge the charge—can be the difference between losing a license for a year and keeping it. If you or your child is facing an underage DUI charge in San Bernardino County, contact Patrick Silva, Attorneys at Law at (909) 500-4819 for a free consultation.

Vehicle Code 23136: The Zero-Tolerance Standard

VC 23136 applies to any driver under 21 with a BAC of 0.01% or higher. It is a civil offense with a one-year license suspension—no jail time, no criminal record, no points on the license.

Enacted by the California Legislature in 1994, Vehicle Code 23136 is the foundation of the state’s underage DUI enforcement. The statute makes it unlawful for a person under 21 to operate a vehicle with a BAC of 0.01% or greater, as measured by a preliminary alcohol screening (PAS) test or other chemical test. There is no requirement that the driver appear intoxicated, drive erratically, or show any signs of impairment.

The 0.01% threshold is extraordinarily low. For context, a 140-pound person could reach that level after consuming less than half a standard drink. Residual alcohol from cooking ingredients, certain cold medications, or alcohol-based mouthwash used shortly before driving could also produce a reading at or above this level.

One critical distinction between VC 23136 and standard DUI: underage drivers cannot refuse the PAS breathalyzer test during a lawful traffic stop. While adult drivers over 21 generally have the right to decline a preliminary breath test before arrest, California’s implied consent provisions treat license holders under 21 as having already agreed to the PAS test. Refusing it triggers a separate one-year license suspension—regardless of whether alcohol was actually present.

Vehicle Code 23140: Underage DUI at 0.05% BAC or Higher

A BAC of 0.05% or higher triggers charges under VC 23140, which is classified as an infraction—a criminal offense, but one that does not carry jail time.

When an underage driver’s BAC reaches 0.05% but stays below 0.08%, California law applies Vehicle Code 23140 in addition to the underlying VC 23136 violation. This is sometimes referred to as “underage DUI” and represents an escalation in both the legal classification and the consequences.

Unlike VC 23136, a violation of VC 23140 is handled through the criminal courts. The penalties for a first offense include a one-year driver’s license suspension, a fine of up to $100, and—for drivers 18 and older—mandatory enrollment in a three-month or longer alcohol education program at the driver’s own expense. Because this is classified as an infraction rather than a misdemeanor, there is no possibility of jail time. However, it does create a court record.

Drivers under 18 charged under VC 23140 will generally have their case processed through the juvenile court system. Drivers who are 18, 19, or 20 face the adult court system, where the infraction is documented on their criminal record. While an infraction is less serious than a misdemeanor, it is still a matter of public record and may appear on background checks.

When an Underage DUI Becomes a Standard Criminal DUI

If an underage driver’s BAC is 0.08% or higher, or if the officer believes driving was impaired at any BAC level, the driver can be charged with standard DUI under Vehicle Code 23152. This misdemeanor charge may carry jail time, steep fines, and a criminal record, particularly in cases involving elevated BAC levels.

Vehicle Code 23152 is the same statute that applies to adults. When it is charged against a driver under 21, the penalties for a first-time misdemeanor DUI offense can include up to six months in county jail, fines totaling up to $1,000 (plus penalty assessments that can push the actual cost significantly higher), a one-year license suspension, mandatory completion of a DUI education program of three to nine months, and three to five years of informal probation.

It is also possible for an underage driver to face charges under VC 23152 even when their BAC is below 0.08%. If the arresting officer observes signs of actual impairment—slurred speech, inability to maintain balance, erratic driving—Vehicle Code 23152(a) allows a DUI charge based on impairment alone, regardless of the specific BAC number. This means a driver under 21 with a BAC of 0.06% could face both a VC 23140 infraction and a VC 23152(a) misdemeanor charge.

A standard DUI conviction as a minor carries consequences that extend well beyond the courtroom. A misdemeanor on a young person’s record can affect college admissions decisions, scholarship eligibility, professional licensing applications, and employment prospects for years. California’s DUI penalties also include mandatory SR-22 insurance filing, which substantially increases auto insurance premiums.

The 10-Day DMV Hearing Deadline

After any underage DUI citation, the driver has exactly 10 days to request an administrative hearing with the California DMV. Missing this deadline means the license suspension takes effect automatically.

The DMV administrative process operates independently from the criminal court case. Even if criminal charges are eventually reduced or dismissed, the DMV can still suspend the license based on the administrative record alone. This is why the 10-day hearing request is so important—it is the only opportunity to challenge the license suspension before it takes effect.

DMV hearings are typically conducted by phone unless the driver requests an in-person hearing. An attorney can represent the driver at this hearing and in many cases can handle it entirely on the driver’s behalf. The hearing examines whether the officer had reasonable cause to believe the driver was under 21 and had consumed alcohol, whether the PAS or chemical test was properly administered, and whether the results showed a BAC at or above the applicable threshold.

If the driver wins at the DMV hearing, the suspension is canceled. If the driver loses, they may be able to request a restricted “critical use” license or file a written appeal within 15 days of the decision.

Defense Strategies for Underage DUI Charges in California

Zero-tolerance laws are strict, but they are not immune to legal challenge. Several defense strategies for underage DUI may apply depending on the circumstances of the stop and arrest:

• Challenging the traffic stop. Officers must have reasonable suspicion of a traffic violation or criminal activity to initiate a stop. If the stop was based on nothing more than the time of night or the driver’s age, any evidence obtained afterward may be suppressed.
• Questioning PAS test accuracy. Preliminary breath testing devices require regular calibration and maintenance. If the device was improperly calibrated, or if the officer failed to follow required testing protocols, the BAC reading may be unreliable.
• Non-alcoholic sources of BAC. Certain medications, mouthwash, and even medical conditions like acid reflux or diabetes can produce false positive readings on a PAS test. If the detected alcohol did not come from an alcoholic beverage, this can form the basis of a defense.
• Rising BAC argument. Alcohol takes time to absorb into the bloodstream. If a driver consumed alcohol shortly before driving, their BAC at the time of the test may have been higher than it was while they were actually operating the vehicle.

Each of these defenses requires an attorney who understands DUI testing procedures, California’s evidence rules, and how to effectively cross-examine the arresting officer at both a DMV hearing and in court.

Juvenile Court vs. Adult Court for Underage DUI

Drivers under 18 typically have their underage DUI case handled in juvenile court. Drivers 18 to 20 face the adult court system and risk a permanent criminal record if convicted of a misdemeanor DUI.

The court that handles an underage DUI depends on the driver’s age and the severity of the charge. Civil violations under VC 23136 do not go through either court system—they are handled entirely through the DMV’s administrative process. Infractions under VC 23140 for drivers under 18 are typically processed through juvenile court, where the focus is on rehabilitation rather than punishment and records are generally sealed.

For drivers who are 18, 19, or 20, the picture changes significantly. VC 23140 infractions and VC 23152 misdemeanor DUI charges are processed through the adult criminal court system. A conviction at this level creates a record that is not automatically sealed and can follow the driver into adulthood—affecting job applications, housing decisions, and professional licensing for years.

This distinction makes it especially important for drivers between 18 and 20 to take underage DUI charges seriously and to seek legal representation as early as possible. A skilled DUI attorney may be able to negotiate a reduction to a lesser charge, secure enrollment in a diversion program, or identify grounds for dismissal that preserve the driver’s record.

Talk to a California DUI Defense Lawyer

An underage DUI charge does not have to define a young person’s future. The zero-tolerance framework is aggressive by design, but that does not mean every charge leads to a conviction or a permanent consequence. Procedural errors, faulty testing equipment, and constitutionally questionable traffic stops all create real opportunities to fight back.

At Patrick Silva, Attorneys at Law, we have spent over a decade defending drivers accused of DUI across San Bernardino County, Riverside County, and the surrounding areas. As a member of the California DUI Lawyers Association and the National College for DUI Defense, Patrick Silva brings specialized knowledge of DUI testing science, DMV administrative procedures, and courtroom defense strategies that general practice attorneys simply do not have.

If you or your child has been cited or arrested under California’s underage DUI laws, don’t wait—the 10-day DMV hearing deadline begins immediately. Call us at (909) 500-4819 for a free consultation to discuss your legal options and start building a defense.