Underage DUI in California: The Zero-Tolerance Law for Drivers Under 21

Reviewed by Ron Chini, Esq. · CA State Bar No. 263308 · DUI defense attorney in Irvine, CA since 2009.
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For a driver under 21, California is far stricter than it is for an adult. While an adult is generally legal up to 0.08% (DRAFT — verify), a minor can lose driving privileges at a blood-alcohol concentration as low as 0.01% (DRAFT — verify) — roughly the trace from a single sip, mouthwash, or cough syrup. What surprises most families is that the harshest first consequence is usually administrative: an automatic one-year license suspension handled by the DMV, often without any criminal charge at all. Understanding which of three tiers applies to your situation is the first step.

This page focuses on what makes an under-21 case different — the zero-tolerance scheme and the license fight. Ron is an experienced DUI defense attorney; he does not claim to be a certified specialist, and no result is ever guaranteed. An arrest is an accusation, not a conviction, and a young person's record and future are worth defending carefully.

Three tiers, set by the breath or blood result

California sorts an under-21 stop into one of three categories based on the alcohol level. They carry very different consequences, and more than one can apply to the same arrest at the same time.

• Zero tolerance — Vehicle Code 23136 (DRAFT — verify): a BAC of 0.01% (DRAFT — verify) or higher. This is a civil/administrative offense — no jail, no criminal conviction — but it triggers an automatic one-year (DRAFT — verify) DMV license suspension. No proof of impairment is required; any detectable alcohol is enough.
• The infraction — Vehicle Code 23140 (DRAFT — verify): a BAC of 0.05% or higher (DRAFT — verify) — this charge has no upper BAC cap, so it can apply on its own or alongside the full DUI below. It is an infraction (like a ticket — no jail), with a first-offense fine of about $100 (DRAFT — verify) plus penalty assessments, a one-year (DRAFT — verify) license suspension, and, for drivers 18 or older, a mandatory alcohol-education program of three months (DRAFT — verify) or longer.
• The full DUI — Vehicle Code 23152 (DRAFT — verify): a BAC of 0.08% (DRAFT — verify) or higher, or actual impairment. This is the same criminal misdemeanor an adult faces — and it stacks on top of the under-21 license consequences. See the DUI penalties overview for the criminal side.

Why a minor can't refuse the roadside breath test

Adults can usually decline the handheld preliminary alcohol screening (PAS) device at the roadside — it's typically optional before arrest. For drivers under 21, it is not. By driving, a minor is deemed to have consented to a PAS test under California's implied-consent rules (Vehicle Code 23136 / 13388) (DRAFT — verify), so the roadside breath test that feeds the zero-tolerance case is effectively mandatory.

Refusing the PAS or other chemical test as a minor carries its own penalty — a license suspension or revocation of one to three years (DRAFT — verify) under Vehicle Code 13353.1 (DRAFT — verify) — and it forfeits the chance at a restricted license. The PAS device is still a machine, though: calibration, maintenance, the 15-minute observation period, and operator error are all reviewable. Learn more about refusing the breath or blood test and the field sobriety tests officers use at the roadside.

The DMV hearing is usually the most important fight

Because the zero-tolerance penalty is the automatic one-year suspension, the DMV administrative hearing is often where an under-21 case is truly won or lost. That hearing is the only way to challenge the suspension — and it does not happen automatically. You (or your attorney) must request it within 10 days (DRAFT — verify) of the arrest, or the suspension takes effect on its own.

At the hearing, the DMV must show the officer had reasonable cause to stop and detain, that the driver was lawfully detained, and that the BAC was 0.01% or higher. Each of those is contestable. This page does not re-explain the hearing process in depth — read the DMV hearing guide for how it works and the deadline.

Suspension, restricted licenses, and SR-22 for minors

A restricted or "critical-need" license is harder to get for a minor than for an adult. The DMV must find a genuine need (school, work, or a family medical situation) with no adequate alternative transportation, and a driver who refused the PAS or chemical test is generally not eligible at all. Even when granted, a mandatory suspension period — often around 30 days (DRAFT — verify) — must usually be served first.

Reinstatement also requires filing an SR-22 proof-of-insurance certificate and paying a reissue fee — about $100 (DRAFT — verify) for an under-21 zero-tolerance suspension. The general mechanics of getting your license back are covered on the license suspension & reinstatement page rather than repeated here.

Why this matters beyond the suspension

For a young driver, the stakes reach past the license. A DUI-related entry can affect delayed or withheld licensing, college admissions and aid, athletic eligibility, military plans, and future insurance costs. Handling the matter early — and, where appropriate, pursuing options like a wet reckless reduction in the criminal case or later expungement — can change the long-term picture. If the case involved drugs rather than alcohol, see drug DUI.

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Ron Chini, Esq.

DUI Defense Attorney · CA State Bar No. 263308

Ron has focused on DUI and criminal defense from his Irvine office since 2009. You work directly with him — not a paralegal or a call center.

Learn more about Ron Chini →