Under-21 DUI Laws in California: BAC Limits and What Happens After an Arrest
California has strict DUI laws for drivers under the age of 21. Unlike adult drivers, minors are subject to a Zero Tolerance law, meaning even a small amount of alcohol in their system can result in penalties.
Depending on the driver’s blood alcohol concentration (BAC), an under-21 DUI case may involve:
- DMV administrative penalties
- an infraction offense
- or a criminal DUI prosecution
Understanding how these laws work can help families and young drivers know what to expect if a DUI stop occurs.
California Zero Tolerance Law (Vehicle Code §23136)
California’s Zero Tolerance law applies to drivers under the age of 21.
Under Vehicle Code §23136(a):
“It is unlawful for a person under the age of 21 years who has a blood-alcohol concentration of 0.01 percent or greater… to drive a vehicle.”
This means a driver under 21 can face penalties even if they are not legally intoxicated.
A violation of this law typically results in:
- DMV administrative action
- one-year driver’s license suspension
- confiscation of the driver’s license by law enforcement
Unlike a criminal DUI case, violations of VC §23136 are usually handled through the Department of Motor Vehicles rather than criminal court.
Law enforcement may determine BAC using breath or blood testing. Our article “DUI Charges in California: Breath & Blood Tests, DMV Process” explains how chemical testing is used during DUI investigations.
Under-21 DUI with 0.05 BAC (Vehicle Code §23140)
California law also creates a separate offense for drivers under 21 who have 0.05% BAC or higher.
Under Vehicle Code §23140(a):
“It is unlawful for a person under the age of 21 years who has 0.05 percent or more… by weight of alcohol in his or her blood to drive a vehicle.”
This offense is typically treated as an infraction rather than a misdemeanor DUI.
Possible penalties may include:
- a fine of approximately $100
- a mandatory alcohol education program
- driver’s license suspension
Although this offense is less severe than a criminal DUI, it can still have consequences for a young driver’s driving record.
When an Under-21 DUI Becomes a Criminal Case
If a driver under the age of 21 has a BAC of 0.08% or higher, prosecutors may file a criminal DUI case under California’s standard DUI statute.
Under Vehicle Code §23152(a):
“It is unlawful for a person who is under the influence of any alcoholic beverage to drive a vehicle.”
Vehicle Code §23152(b) further states:
“It is unlawful for a person who has 0.08 percent or more… by weight of alcohol in his or her blood to drive a vehicle.”
When charges are filed under VC §23152, the case is typically prosecuted as a misdemeanor criminal DUI and may involve:
- DUI probation
- fines and penalties
- DUI education programs
- license suspension
- possible jail time depending on the circumstances
Penalties may increase significantly for repeat offenses. For more information about enhanced penalties, see our article “2nd DUI in California: Penalties, Laws & Defense Options.”
In some cases, drivers convicted of DUI may also be required to install an ignition interlock device (IID) before driving privileges are restored. Learn more in “California IID Laws 2026 | San Bernardino DUI Guide.
BAC Levels for Drivers Under 21 in California
California law treats under-21 DUI cases differently depending on the driver’s BAC level.
BAC Level | Law | Type of Case |
|---|---|---|
0.01 – 0.04 | VC §23136 | Zero Tolerance (DMV suspension) |
0.05 – 0.07 | VC §23140 | Infraction offense |
0.08+ | VC §23152 | Criminal DUI |
Each situation depends on the facts of the case and the evidence gathered during the traffic stop.
Evidence Used in Under-21 DUI Investigations
Law enforcement officers may rely on several types of evidence during a DUI investigation, including:
- officer observations
- driving behavior
- breath or blood test results
- statements made by the driver
During many DUI investigations, officers also conduct field sobriety tests, which are often used as evidence in DUI cases. Our article “Failed a Field Sobriety Test? Here’s What You Need to Know” explains how these tests are used during DUI investigations.
What Happens After an Under-21 DUI Arrest?
If a driver under 21 is cited or arrested for DUI, the process may involve several steps.
These may include:
- a traffic stop or DUI investigation
- chemical testing for BAC
- a notice of license suspension
- a possible DMV hearing
- a court appearance if criminal charges are filed
The driver typically has 10 days to request a DMV hearing to challenge a license suspension.
To understand the DUI process in more detail, see our article “What Happens After a DUI Arrest in California?”
Defending Under-21 DUI Charges
Under-21 DUI cases may involve reviewing several factors related to the traffic stop and investigation, including:
- The legality of the traffic stop
- Breath testing procedures
- BAC testing accuracy
- Officer observations during the stop
During many DUI investigations, officers conduct field sobriety tests, which are often used as evidence during a DUI case. Learn more about how these tests are used in our article Failed a Field Sobriety Test? Here’s What You Need to Know.
Because under-21 DUI cases can involve both DMV administrative issues and criminal court proceedings, it is important to carefully review all aspects of the investigation.
FAQ: Under-21 DUI in California
Can someone under 21 get a DUI with a BAC under 0.08?
Yes. Drivers under 21 may face penalties under California’s Zero Tolerance law (VC §23136) with a BAC of 0.01% or higher, even if they are not legally intoxicated.
What happens if a minor has a BAC of 0.03?
A BAC of 0.03 would typically fall under the Zero Tolerance law, which may result in a driver’s license suspension handled through the DMV.
Is a 0.05 BAC a criminal DUI for someone under 21?
Not usually. A BAC of 0.05 or higher may result in an infraction offense under Vehicle Code §23140, which carries fines and alcohol education requirements.
When does an under-21 DUI become a criminal case?
A DUI may become a criminal case if the driver has a BAC of 0.08% or higher under Vehicle Code §23152, or if prosecutors believe the driver was impaired.
Speak With a Criminal Defense Attorney
If you or a family member is facing a DUI investigation or charges in Southern California, understanding your legal options early can be important.
The Law Offices of Kirk Tarman & Associates represents clients facing DUI and criminal charges throughout San Bernardino County, Riverside County, Los Angeles County, and Orange County.
Our office offers free consultations, and we also have a live team member available after hours who can answer initial questions and schedule an appointment with our legal staff.