A marijuana DUI is punished the same way as an alcohol DUI in California. A first offense typically means fines, up to six months of county jail exposure, a license suspension, DUI school, and three to five years of probation. The penalties climb with each prior offense, just like alcohol cases.
What's different is how the state proves it. There's no BAC-style legal limit for THC. Unlike the 0.08% alcohol number, California has no set nanogram threshold that automatically means you're impaired. That cuts both ways. The prosecution can't just point to a number, so they lean on the officer's observations, a drug recognition evaluation, and a blood test showing THC in your system.
The problem with that blood test is timing. THC can linger in your blood for days or even weeks after use, long after any impairment has worn off. A positive result doesn't prove you were high behind the wheel, and that gap is a real weakness in many cannabis DUI cases. Regular users can carry measurable THC while completely sober.
Defenses often focus on that disconnect between the presence of THC and actual impairment, along with the usual challenges to the stop and the officer's conclusions.
Read more on the marijuana DUI page and the drug DUI page.
This is general information, not legal advice, and every case is different. For a free consultation, call (858) 622-7280 or visit /contact.