Medical Marijuana and Driving

Medical marijuana users might think it's legal for them to drive while under the influence of marijuana, but this is not the case.

Most people are aware that it's illegal to drive under the influence of alcohol and drugs, including marijuana. But if you live in one of the 18 states that have made it legal to use marijuana for medical purposes, you might think that as long as you carefully follow the medical marijuana rules, it's okay to operate a vehicle at the same time. Not so--none of the states permit medical marijuana users to drive while under the influence of the drug. These states  reason that an impaired driver is an unsafe driver, regardless of the reason for the impairment--recreational use or medical treatment.

In some states, it is a defense to DUI charges to show that the driver was entitled to use a prescription medication while driving, but marijuana is always excluded from this exception.

To avoid DUI charges, medical marijuana patients should be aware of the rules they are expected to follow when they consider driving after their treatments or use. Penalties for DUI convictions can include harsh fines, jail time, or both.

Driving Lawfully as a Medical Marijuana Patient

Marijuana patients often wonder how they can avoid DUI charges after using medicinal marijuana. The answer starts with an of understanding how your state treats marijuana DUI charges.

To be convicted of a DUI, the prosecutor must first show that the driver was “under the influence” of marijuana (or another drug). State laws vary according to how they define being “under the influence”, with the consequences to drivers who use medical marijuana dependant on which method their state uses. States usually fall into one of three categories regarding marijuana DUI charges:

  • Any amount = under the influence. In some states, any amount of marijuana in the driver’s system will conclusively establish that the driver was under the influence. These states have what's known as a "per se" approach.
  • Above the threshold = under the influence. In other states a driver who is above a certain blood or urine concentration level will be considered under the influence.
  • The defendant’s behavior or actions= under the influence. A minority of states require the prosecutor to prove that the driver was under the influence, by pointing to his behavior or driving, regardless of the amount of marijuana in the driver’s system.

To learn more about these definitions, see Driving Under the Influence of Marijuana; and for more about how your state defines being “under the influence”, click the link to your state under the "Marijuana DUI Laws by State" section of that article.

Patients in per se  states

Medical marijuana patients must be especially careful in states that apply the per se approach (any marijuana in the driver's system = under the influence). In these states, the prosecutor can easily prove that the driver was under the influence by pointing to any amount of marijuana in the driver’s system, and needn’t show any evidence of actual impairment (such as slurred speech or inability to safely handle the vehicle). Indeed, the prosecutor does not have to show impairment at all – merely being under the influence is enough to support the DUI charge.

If you are involved in an accident (even if it is not your fault) or are pulled over for another reason, you might nonetheless be subject to a drug test. As long as there is any trace of marijuana in your system—even if the last time you used medicinal marijuana was several days or more ago— the officer can then also arrest you for a marijuana DUI.

Non per se states

In states that require either a threshold amount or evidence of being under the influence as proof of being under the influence, medical marijuana patients have more control over whether their marijuana use will land them in front of a judge on DUI charges. As long as they stay under the legally-imposed blood concentration limits, or are not actually under the influence, they may be able to avoid charges and prosecution. For example, while this may be easier said than done, it is possible to get a general sense of your concentration levels at various points in the days following your medical treatments. And you can avoid driving immediately following a dose of medicinal marijuana.

Practically speaking, a lot also depends on the judge that hears your case. For more information, see the section entitled “Get Legal Help for a Marijuana DUI Charge,” below.

Short of not driving at all, it may be difficult to steer entirely clear of marijuana DUI charges, but knowing your state’s laws—and working to stay within them—can help to greatly reduce such chances.  

Punishments for Driving Under the Influence of Marijuana

Penalties for a marijuana DUI—even after medicinal use—can include fines, jail time, probation, and more. These sentences often increase when the DUI involved so-called “aggravating factors”, such as a DUI with a minor passenger in the vehicle, or for second and subsequent offenses. To learn more, see Driving Under the Influence of Marijuana.

Get Legal Advice on Driving as  a Medical Marijuana Patient  (or Help for a Marijuana DUI Charge)

If you haven’t been charged with a DUI, a local lawyer can inform you as to ways you can stay within the law as a medical marijuana patient who drives a vehicle. Remember, your best bet is avoiding DUI charges to begin with.

Driving under the influence of marijuana is a serious charge, even if it is at the misdemeanor level. With this type of conviction on your record, your ability to obtain employment under certain circumstances may be limited. Insurance will become very hard to obtain and your premiums will surely go up. And as you now know, if you are convicted of a DUI again, you will face the possibility of enhanced punishments.

For these reasons, most people charged with a DUI will benefit from the assistance of a good criminal defense attorney. Be sure the lawyer you choose has experience with DUI cases in particular—it’s a subspecialty, and you’ll want a local attorney who knows how these cases are handled by the prosecutors and judges who will be involved in your case. Your lawyer can evaluate the strength of the evidence against you, explain your options (which might include a plea of guilty to a lower charge, such as reckless driving), assess your chances of winning if you go to trial, give you the straight scoop on the consequences you’re likely to face if you lose, and protect your rights.

Marijuana DUI Laws by State

Choose your state from the list below to find information about your states marijuana DUI laws.  


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