Alcohol and drugs
You are 19 years old. At what blood alcohol concentration (BAC) does it become illegal for you to drive in California?
- 0.01% or higher. Correct answer
- 0.05% or higher.
- 0.08% or higher.
Why
California applies a zero-tolerance standard to drivers under 21: a BAC of 0.01% or higher is illegal. The 0.08% limit is the one for drivers over 21, and lower limits apply to commercial drivers and drivers carrying passengers for hire (0.04%) and to anyone on DUI probation (0.01% at any age). The 0.05% figure has a real meaning for under-21 drivers, but it is not a limit: a preliminary alcohol screening at 0.05% or more lets the officer demand a breath or blood test, and when that later test reads the same figure, a DUI arrest and the loss of the driving privilege are both on the table. A DUI conviction under 21 lets DMV revoke the driving privilege for a year and requires completing a licensed DUI program, and refusing a chemical test costs the driving privilege for a year on its own.
Where this comes from
California Driver's Handbook, June 2025 edition. The correct answer is 0.01% or higher.
The rule behind this one
California alcohol and drug rules for drivers goes through the whole topic, with the page of the California Driver's Handbook behind every rule.
More on alcohol and drugs
- You are carrying a bottle of wine that has already been opened. Where may it legally ride in your car?
- A law enforcement officer suspects you of driving under the influence and asks you to take a breath, blood, or urine test. What happens if you refuse?
- How long does a DUI conviction stay on your California driver's record?
- You are 30 years old and not on DUI probation. You are driving your own car, which needs no commercial license and carries no passengers for hire. At what blood alcohol concentration (BAC) does it become illegal for you to drive?