Marijuana DUI in Illinois

Driving under the influence of cannabis can result in significant legal and administrative penalties in Illinois. Although recreational marijuana use became legal in the state on January 1, 2020, legalization did not alter the prohibition against operating a motor vehicle while impaired by cannabis. Illinois law establishes specific thresholds for cannabis intoxication while also allowing for DUI charges based on observed impairment. This page outlines the current legal standards, a brief history of marijuana DUI laws in Illinois, penalties, license consequences, and how our firm assists with driver’s license reinstatement following a marijuana-related DUI.

Legal Thresholds for Cannabis Intoxication in Illinois

Illinois law defines cannabis intoxication under Section 11-501 of the Illinois Vehicle Code. Pursuant to the law, a person can be found guilty of a marijuana-related DUI if they operate or are in actual physical control of a vehicle while under the influence of cannabis to a degree that renders them incapable of safely driving.

Additionally, Illinois law imposes a per se standard based on the concentration of THC in the driver’s blood. If a driver has a tetrahydrocannabinol (THC) concentration of five nanograms or more per milliliter of whole blood, or ten nanograms or more per milliliter of another bodily substance such as saliva or urine, the law presumes intoxication.

Even if the driver’s THC level is below the statutory threshold, an officer can still charge DUI if there is evidence of impairment. This can include poor performance on standardized field sobriety tests, erratic driving, admissions of use, the presence of cannabis in the vehicle, or the odor of marijuana.

Historical Background of Marijuana DUI Laws in Illinois

Historically, Illinois enforced a zero tolerance policy for cannabis in drivers. Under the former provision 11-501(a)(6) provision of the DUI statute, it was unlawful to operate a motor vehicle with any trace of a cannabis metabolite in the body, regardless of impairment or recency of use. The former standard resulted in DUI convictions for individuals who were no longer impaired while driving but still had residual THC metabolites in their system.

This strict standard was challenged in courts and raised constitutional concerns, especially after Illinois legalized medical marijuana in 2013. As a result, the state amended its DUI statute to account for active impairment rather than mere presence of metabolites. The revision introduced the five nanograms per milliliter blood threshold, aligning Illinois with other states that use a similar per se limit.

Importantly, the legalization of cannabis for recreational or medical use does not serve as a defense to DUI charges. Section 11 501.2(c) of the Illinois Vehicle Code explicitly states that legal entitlement to use cannabis is not a defense to a charge under Section 11-501. It is still an offense to drive under the influence of cannabis, even if the cannabis was obtained and used lawfully.

Affirmative Defenses to Marijuana DUI in Illinois

Under Illinois law, an affirmative defense requires the defendant to present evidence that, if believed, would negate criminal liability. In the context of marijuana DUIs, a common misunderstanding is that possession of a medical marijuana card or a lawful purchase receipt serves as an affirmative defense – it does not.

The strongest affirmative defense in a cannabis DUI case is the lack of active THC in the system or lack of impairment. For example, if a driver had only inactive cannabis metabolites in the body and showed no signs of impairment, that may be used to argue that the driver was not impaired while driving. Toxicology reports showing THC concentrations below the statutory threshold can also be used as evidence in the defense, but these are often rebutted by officer testimony or video evidence of poor driving performance.

Other defenses to a marijuana DUI focus on the legality of the traffic stop, the validity of field sobriety tests, and the scientific accuracy of the blood or saliva testing. However, these are not affirmative defenses but rather legal challenges to the admissibility of the evidence or the lawfulness of the arrest.

Penalties for a First Marijuana DUI in Illinois

A first offense for driving under the influence of cannabis is typically charged as a Class A misdemeanor, so long as no aggravating factors are present. A Class A misdemeanor is punishable by up to 364 days in jail and/or a fine of up to 2,500 dollars.

If the DUI involved aggravating factors, such as driving in a school zone, involvement in an accident resulting in bodily harm, or driving with a passenger under the age of 16, the charge may be elevated to a felony.

With first-time marijuana DUI offenders, court supervision and mandatory participation in a drug education or treatment program are common alternatives to jail time for the misdemeanor charge. If given court supervision, a first-time offender does not have their Illinois driver’s license revoked.

Driver’s License Revocation for Marijuana DUI in Illinois

If supervision is not granted, a conviction for a first-offense marijuana DUI leads to a mandatory revocation of driving privileges. This revocation is separate from any statutory summary suspension that may have been imposed at the time of arrest. A statutory summary suspension occurs automatically if the driver fails chemical testing or refuses to submit to testing. For those who fail the test, the suspension lasts six months. For first-offenders who refuse testing, the suspension last twelve months.

Once the revocation period ends, driving privileges are not automatically restored. The individual must apply for reinstatement through a formal hearing with the Illinois Secretary of State. This hearing process can be complex and requires documentation of rehabilitation, which can include a current drug/alcohol evaluation, as well as proof of successful completion of treatment or education.

Drivers may be eligible for a Monitoring Device Driving Permit (MDDP) or a Restricted Driving Permit (RDP) during the suspension or revocation period, depending on the circumstances of the offense and prior driving history. These permits often require the installation of a breath alcohol ignition interlock device (BAIID).  

Driver’s License Reinstatement After a Marijuana DUI

Wirth Law provides experienced legal representation to individuals seeking driver’s license reinstatement following a DUI involving marijuana. The reinstatement process requires careful preparation, extensive documentation, and a persuasive presentation at a hearing before the Secretary of State.

Our office serves clients in Chicago, Naperville, and throughout Illinois who are navigating the aftermath of a marijuana-related DUI. We regularly assist individuals in Cook, Will, Kane, Kendall, Lake, Kankakee, Dekalb, and Winnebago Counties, offering dedicated representation to those facing complex driver’s license suspension or revocation issues. Wirth Law also represents out-of-state residents who have an Illinois hold on their driving privileges, helping clients across the country navigate the process of clearing their Illinois record so they can drive legally again.

Our practice is known for its exceptional client service and strong record of success in DUI defense and license reinstatement matters. Jennifer Wirth, managing attorney, has received multiple awards recognizing her commitment to client advocacy, including perfect “10” ratings on Avvo and Justia, the Martindale-Hubbell Client Champion Award, and selection as one of the top DUI defense attorneys in Chicago by Expertise.com. Her approach to legal representation is grounded in professionalism, compassion, and an in-depth understanding of Illinois Secretary of State hearing procedures.

At Wirth Law, every client is treated with respect and care. Our firm prioritizes clear communication, ensuring that individuals fully understand their legal options so they can make informed decisions about their case. Whether dealing with a first-time suspension or a more complex revocation after multiple DUIs, clients can expect honest guidance and skilled representation throughout the reinstatement process.

Wirth Law offers free consultations, affordable flat fees, and payment plan options through Affirm to make legal services more accessible. To schedule a consultation, contact Wirth Law at (312) 761-8290 or email jennifer@wirthlaw.org.

Further Reading: Illinois DUI Defense

• Area of Practice: Illinois DUI Defense
• Overview of a First DUI in Illinois
• Illinois Statutory Summary Suspension Law
• Aggravated DUI in Illinois
• Out-of-State DUI: Suspensions and Revocations
• Type A Injury DUI Cases
• CDL Consequences for an Illinois DUI
• Underage DUI and Zero Tolerance
• Marijuana DUI
• Prescription Drug DUI
• DUI Chemical Testing