Driving under the influence of marijuana is illegal in all 50 states, in D.C., and on federal land. A first offense is normally a misdemeanor: a fine somewhere between a few hundred and a couple thousand dollars, a license suspension, DUI education classes, and sometimes a short jail term or probation. A crash, a prior DUI, or a kid in the back seat pushes the charge toward felony territory.
penalties for driving high on marijuana
The charge is a DUI, not a cannabis ticket
Most states don't have a lighter, marijuana-only offense. Prosecutors file it under the same DUI statute they use for alcohol, sometimes with a drug-specific subsection. The collateral damage looks identical too: a criminal record, insurance rate hikes, employment background checks, and ignition interlock requirements in states that mandate it for all DUI convictions.
What Happens If You Get a DUI for Weed
Two ways states try to prove you were impaired
Per se states set a blood THC number. Colorado and Washington use 5 ng/mL of active THC, Illinois uses 5 ng/mL for THC or 10 ng/mL for metabolites, and several others have similar thresholds. A handful run zero-tolerance rules where any detectable metabolite counts.
what is the legal limit for weed while driving
Impairment states have no number at all. The officer testifies about weaving, speed, field sobriety tests, and what they saw in your eyes and speech. The blood result becomes one piece of evidence instead of the whole case. Some zero-tolerance states have carved out protections for registered medical patients after court challenges, so the details matter where you live.
How is Cannabis Impairment Measured While Driving
What a first offense usually costs
- Fines and fees: roughly $500 to $2,500, plus court costs and assessments
- License suspension: 30 days to a year, sometimes with a restricted license option
- Jail: often suspended, but a day or two is common in some jurisdictions
- DUI education or treatment: 8 to 16 hours minimum, longer if a substance evaluation is ordered
- Insurance: rates frequently jump 30 to 80 percent and stay there for years
What makes it worse
An injury crash, a combination of alcohol and THC, prior DUI convictions, a suspended license, a minor in the vehicle, a school zone, or refusing a chemical test in an implied-consent state. Each of those adds penalties on top of the base charge, and a few of them turn a misdemeanor into a felony with real prison exposure.
The medical card question
In most states a medical card is not a defense to a DUI charge. It may explain a positive test or help at sentencing, but it doesn't make impaired driving legal. A small number of states give registered patients an affirmative defense if they can show they weren't actually impaired. I would not count on it without a local attorney reading the statute.
Why the THC test is such a mess
Blood THC peaks fast and falls within hours, while metabolites linger for days or weeks. A regular user can test positive on a Sunday morning with nothing in their system that affects driving. That gap is why impairment states lean on behavior evidence, and why per se laws keep getting challenged in court.
Commercial drivers and federal land
CDL holders face stricter standards and longer disqualification periods, and a cannabis DUI can end a driving career. Federal land, military bases, and national parks follow federal law, where cannabis remains illegal regardless of what your state allows.