You can be arrested for driving stoned, even in states where cannabis is legal

Driving under the influence of cannabis is illegal everywhere in the United States, regardless of whether your state allows recreational or medical use. The law treats it the same way it treats alcohol: you can possess it legally, but you cannot operate a vehicle while impaired by it. Police can arrest you, you can lose your license, and you can face criminal charges — the consequences are identical to a DUI.

The complication is that unlike alcohol, there is no legal threshold for cannabis impairment that applies everywhere. A breathalyzer gives a number; a cannabis test does not. This means the arrest and conviction depend partly on what a police officer observes, what a blood or saliva test shows, and what your state's specific law says about THC levels.

Key Takeaways

  • Driving stoned is a criminal offense in all 50 states, even in states where cannabis is legal to buy and use.
  • Police do not need a breathalyzer equivalent — they can arrest based on a failed field sobriety test, observed impairment, or a positive drug test.
  • A conviction typically results in license suspension, fines, mandatory drug education, and a criminal record that affects insurance and employment.
  • Some states set a legal THC blood level (usually 2 to 5 nanograms per milliliter), but exceeding it does not automatically prove impairment the way a BAC does.

How police detect and charge cannabis impairment

A police officer who suspects you are driving stoned will typically start with a traffic stop and observation — slurred speech, red eyes, slow reaction time, or the smell of cannabis. They may ask you to perform a field sobriety test: walk a straight line, stand on one leg, or follow a pen with your eyes. These tests are subjective and designed to be difficult even for sober people, but they give the officer grounds to request a blood or saliva test.

If you refuse the test, most states allow the officer to obtain a warrant for your blood. If you take the test and it shows THC, the result becomes evidence. However, THC stays in your bloodstream for days or weeks after the high wears off, so a positive test does not prove you were impaired at the time of driving — only that you used cannabis recently. Some states recognize this problem and set a legal threshold (2 to 5 nanograms of THC per milliliter of blood), but others do not, meaning any detectable THC can be used against you.

Criminal penalties for driving stoned

A first-time conviction for driving under the influence of cannabis typically results in license suspension (usually 6 months to 1 year), fines ranging from $500 to $2,000, and mandatory enrollment in a drug education or treatment program. You will also have a criminal record, which affects background checks for employment, housing, and professional licenses.

A second or subsequent conviction carries steeper penalties: longer license suspension (often 1 to 3 years), higher fines, possible jail time, and an ignition interlock device requirement in some states. The criminal record compounds over time, and insurance companies will raise your rates or drop you entirely after a DUI conviction of any kind.

How cannabis impairment differs from alcohol impairment

Cannabis affects different people differently, and the effects depend on the dose, the method of consumption, and individual tolerance. Smoking or vaping produces effects within minutes and peaks within 30 minutes to 2 hours. Edibles take 1 to 2 hours to kick in but can last much longer and produce stronger effects. Some people feel impaired; others do not, even at the same dose.

This variability is why police rely on observed behavior rather than a single number. A breathalyzer tells you someone's blood alcohol content; a drug test tells you someone used cannabis, not whether they are impaired right now. This makes cannabis DUI cases harder to prosecute in some states but easier in others, depending on how the law is written and whether the prosecutor can show impairment through other evidence.

What happens to your insurance and driving record

A DUI conviction — whether for alcohol or cannabis — is reported to your state's Department of Motor Vehicles and becomes part of your permanent driving record. Insurance companies see this record and treat you as a high-risk driver. Your premiums will increase by 50% to 100% or more, and some insurers will straightforward refuse to cover you. You may be forced to buy high-risk insurance, which costs significantly more.

The conviction also affects your ability to drive professionally. If you drive for a living — as a rideshare driver, delivery driver, or commercial driver — a DUI conviction can end your ability to work in that field. Many gig economy platforms and commercial driving jobs require a clean driving record and will deactivate or terminate you after a conviction.

State-by-state variation in cannabis DUI laws

A handful of states have set specific legal THC thresholds, similar to the 0.08% blood alcohol limit. Colorado, Washington, and Montana use 5 nanograms per milliliter; Ohio uses 2 nanograms. However, these thresholds do not work the same way as a BAC limit — exceeding the threshold does not automatically prove impairment, and staying below it does not prove you were not impaired. Prosecutors must still show that your driving was affected.

Most states have no legal threshold and instead rely on "impairment-based" DUI laws, which mean any amount of cannabis in your system combined with observed impairment can result in a conviction. This gives prosecutors more flexibility but also creates inconsistency: the same behavior might result in a conviction in one state and acquittal in another.

Frequently Asked Questions

Does cannabis stay in your system long enough to fail a test the next day?

Yes. THC can be detected in blood for 24 to 48 hours after use, and in urine for weeks. A positive test does not mean you were impaired while driving, only that you used cannabis recently. Some states recognize this distinction; others do not.

What should I do if I am pulled over and the officer suspects I am stoned?

Remain calm and polite. You have the right to refuse a field sobriety test and to speak with a lawyer before answering questions. In most states, refusing a blood or breath test results in automatic license suspension, but it also prevents the test result from being used as evidence. Consult a DUI attorney in your state for specific guidance.

Can I get a DUI for cannabis if I am in a state where it is legal?

Yes, absolutely. Legal possession does not mean legal driving. Every state prohibits driving under the influence of cannabis, regardless of whether the drug itself is legal. The legality of possession and the legality of driving while impaired are separate questions.

Will a cannabis DUI show up on a background check?

Yes. A DUI conviction is a criminal record and will appear on background checks for employment, housing, and professional licenses. Some employers and landlords will reject applications based on this record alone.

How long does a DUI conviction stay on my record?

In most states, a DUI conviction remains on your driving record permanently. Some states allow expungement (removal from public record) after a certain period, typically 5 to 10 years, but you must petition the court. Insurance companies may consider it for 3 to 10 years regardless of expungement.