Underage DUI in California: Three Different Laws, and Which Court Hears the Case

“Underage DUI” sounds like the name of one California offense. It is not. The phrase may refer to the under-21 zero-tolerance law, a separate under-21 0.05 allegation, an ordinary DUI charge that applies regardless of age, or an administrative DMV action arising from the same event.

Those routes do not ask the same question, and the number on the printout will not tell you which one you are in. A reported 0.01, 0.05, or 0.08 result does not, by itself, identify the pending statute, the proof required, or whether the paper in your hand belongs to the DMV, adult criminal court, or juvenile court.

Start with what you can pin down first: the driver's age on the incident date, and the statute printed on every paper. Then identify the test, the complete DMV order, and the court named on the citation, complaint, or petition. That turns one frightening label into a set of questions someone can actually answer.

One number on the printout can point to three different laws.

Vehicle Code section 23136 (opens in a new window) is commonly called the zero-tolerance law, and it's probably the one you have heard of. It is not another name for the ordinary 0.08 provision, and it should not be described as only a DMV rule: section 23136 can appear in the citation or court record, while the same event may also produce an administrative action.

Vehicle Code section 23140 (opens in a new window) supplies the separate under-21 0.05 route. Vehicle Code section 23152 (opens in a new window) contains the ordinary DUI provisions. Section 23136 expressly says it does not prevent prosecution under section 23152 or section 23153, so more than one allegation may arise from the same driving event.

That does not make the thresholds interchangeable. Each count and each administrative action has to be matched to its own statute, its own decision-maker, and its own evidence, and that sorting is the job in front of you.

If section 23140 is the number on the paper, the Judicial Council's 2026 criminal jury instruction states the three proof questions directly: whether the person drove, had a blood-alcohol level of 0.05 percent or more at that time, and was then under 21.

Age affects the legal rule, court forum, and communication.

For sections 23136 and 23140, the first question is whether the person was under 21 when the alleged driving occurred, so find reliable proof of the birth date and the incident date and keep it with everything else. A report's use of “minor,” “juvenile,” or “underage” is not precise enough to answer that question for you.

A driver who was 18, 19, or 20 is an adult for California court procedure even though the under-21 alcohol statutes may apply. If a prosecutor files an adult charge, the complaint and arraignment identify the court case, and the prosecution must prove the charge beyond a reasonable doubt.

A person who was under 18 at the time of the event generally requires a juvenile-procedure analysis: different paper, and different rules. The California Courts explains that a juvenile case begins with a petition and that a judge, rather than a jury, decides whether the petition's allegations were proved beyond a reasonable doubt. Read the actual petition, the court named on it, and the case number before assuming which forum and which procedure you are in.

Age also changes what a parent is allowed to do. A parent can help collect papers, arrange transportation, and track dates. If the driver is 18 or older, though, the driver — not the parent — controls whether a lawyer may share confidential information with a parent. When the driver is a minor, the parent may have a formal role, but counsel should explain the youth's rights and the limits of family participation.

The under-21 testing record follows a distinct statutory sequence.

Advice about roadside testing for an over-21 driver should not be copied into an under-21 case. Section 23136 contains a testing provision that applies when an under-21 driver is lawfully detained and the officer has reasonable cause to believe the driver violated the section.

In that setting, the statute treats the driver as having consented to a preliminary alcohol screening test or another chemical test requested under the provision. Vehicle Code section 13388 (opens in a new window) addresses the officer's request for a preliminary screening test when a device is immediately available and another chemical test when it is not.

This describes how to review an event that has already occurred; it is not advice to refuse or delay a future test. If you are trying to reconstruct that sequence, these are the questions to write down and answer one at a time:

• What supported the lawful detention and the officer's claimed reasonable cause?
• Which test was requested, at what point, and with what advisement?
• Was a preliminary screening device immediately available?
• What did the driver say or do in response?
• Was a sample completed, interrupted, or reported as insufficient?
• Which instrument or laboratory produced the result, and when?

A report may compress the whole encounter into a single word: “refused” or “failed.” Video, audio, device records, existing medical information, and the timing of each attempt may provide a more exact account. Preserve those sources rather than writing a replacement explanation of your own.

The DMV order starts a clock, and it is not the court date.

Vehicle Code section 13353.2 (opens in a new window) includes an administrative trigger for a driver under 21 with a reported alcohol concentration of 0.01 or more. Vehicle Code section 13353.1 (opens in a new window) contains a separate refusal-or-failure framework. The notice should identify the action and statutory authority; one should not be assumed from the other.

The DMV conducts an administrative review. A requested hearing allows the driver to contest the facts assigned to the particular action. In a reported-result matter, the questions can include age, reasonable cause, lawful detention, driving, and the result. A refusal matter focuses on a different record, including the request and response.

The DMV's April 2026 Driver Safety guide says a hearing generally must be requested within 10 days after receipt of a notice or within 14 days from the date of a mailed notice. Do not count forward from the day of the arrest and assume you know the date. Compare that guidance with the order that was actually served, how it was served, what proof of receipt exists, and the instructions printed on it. The 10-Day Rule guide explains the notice-specific response without assuming that every deadline runs from the arrest.

A hearing request does not, by itself, establish present authority to drive or automatically pause the action. So before anyone gets back behind the wheel, confirm current status from the written DMV record. And the length of any suspension is not something that can be read off the stop: a universal suspension period or restriction result cannot be inferred without first reviewing the governing route, service, test or refusal record, prior history, and current licensing provisions.

The same test result may be doing two different jobs at once.

The DMV hearing concerns the action named in the order. It does not decide criminal guilt. Adult criminal court or juvenile court addresses the allegations filed in that proceeding under the applicable rules.

A test result may appear in both files without doing the same legal work. A 0.01 result may support a zero-tolerance administrative action. A 0.05 result may be offered for section 23140. A 0.08-or-higher result may be offered under the ordinary per se provision. Driving, observations, and other evidence may support an impairment theory even when the prosecution is not relying on a particular alcohol number.

The prosecution must prove the elements of the filed court allegation. The DMV must decide the facts assigned to its administrative action. The DMV hearing versus criminal court guide explains the different papers, burdens, calendars, and limited statutory interactions.

That is why you keep two folders and two lines on the calendar. If the same recording or report belongs in both, list it once in one evidence index, but write down what question it answers in each proceeding.

Match the evidence to the statute printed on the paper.

If the paper says section 23136, gather proof of age and driving, the basis for the detention, the test type and timing, and the reported 0.01-or-more result. If the DMV order alleges refusal or failure instead, keep that exchange and its legal questions separate.

For section 23140, identify age, driving, sample identity, collection time, reported 0.05-or-more result, and the foundation for that result. Do not treat the DMV order as proof that a court charge was filed.

If it says section 23152, find the subsection first; it decides which case is actually being made. An impairment count may rely on driving, witness observations, video, field exercises, statements, and test evidence. A per se count focuses on the statutory alcohol level and timing. Drug and combined-influence allegations require a different toxicology and impairment inquiry.

The California DUI evidence guide explains how to audit the stop, driving, observation, field-exercise, breath, and blood records without treating a discrepancy as an automatic result.

Family help should preserve the record without taking over the case.

Keep all of it: the citation, the release paper, the DMV order, the envelope it arrived in, the complaint or juvenile petition, the court notice, the test paperwork, and every page provided by law enforcement. Preserve original messages, receipts, photographs, location information, and existing medical records that may bear on the timeline.

Write a private chronology that separates what the driver remembers, what another person said, and what a document reports. Do not send it to friends for correction, post about the event, or ask anyone to align accounts.

A family seeking counsel should confirm whether the engagement includes the DMV proceeding, the adult or juvenile court matter, or both. Juvenile defense, family participation, and any need for separate counsel should be discussed explicitly rather than inferred from a general DUI service description.

Official Sources

• California Vehicle Code § 23136 (opens in a new window)
• California Vehicle Code § 23140 (opens in a new window)
• California Vehicle Code § 23152 (opens in a new window)
• California Vehicle Code § 13353.1 (opens in a new window)
• California Vehicle Code § 13353.2 (opens in a new window)
• California Vehicle Code § 13388 (opens in a new window)
• California Vehicle Code § 13557 (opens in a new window)
• California Vehicle Code § 13558 (opens in a new window)
• California DMV: Driver Safety Administrative Hearings Process, revised April 2026 (opens in a new window)
• Judicial Council of California: 2026 Criminal Jury Instructions (opens in a new window)
• California Courts: Juvenile Court Process (opens in a new window)

Before anyone guesses at the outcome, find out which law this is.

Bring the whole pile to a case-specific review: proof of age, the complete DMV order and proof of receipt, the citation, the complaint or juvenile petition, the release terms, the test papers, the current driving record, and your private chronology. The first task is not predicting what happens. It's determining whether section 23136, section 23140, section 23152, a refusal provision, or more than one route actually appears.

Boyadzhyan Legal Shield provides DUI defense as part of our criminal-defense practice. Initial consultations are free, confidential, and carry no obligation to hire the firm. Learn more about California DUI defense or request a consultation.

This article provides general information, not legal advice. Under-21 testing duties, administrative action, adult or juvenile court procedure, current driving status, and the effect of a specific notice or charge require current, case-specific review by a California attorney.