Can You Be Charged With DUI for Marijuana in Tennessee?

 Posted on April 28, 2026 in DUI/DWI/BUI

You can be charged with DUI for marijuana in Tennessee. Unlike alcohol, there is no legal limit for THC in Tennessee that automatically triggers a DUI. Instead, the charge is based on whether the drug impaired your ability to drive safely. If you are facing this situation in 2026, a Farragut, TN DUI defense lawyer can help you understand what the state has to prove and how to fight the charge.

How Does Tennessee Define DUI for Marijuana?

Tennessee Code Annotated § 55-10-401 defines DUI broadly. It is illegal to drive or be in physical control of a vehicle while under the influence of any intoxicant, including marijuana, to a degree that causes impairment. The law does not require a specific blood THC level to charge someone. The state is simply required to show that marijuana in your system affected your ability to drive.

This is different from alcohol DUI cases, where a blood alcohol content of 0.08 percent or higher creates a legal presumption of impairment. With marijuana, the state has to build its case around evidence of actual impairment rather than relying on a number alone.

What Evidence Does the State Use To Prove Marijuana DUI in Tennessee?

Because there is no automatic legal limit for THC in Tennessee, prosecutors rely heavily on other types of evidence to prove impairment. The most common types of evidence used in marijuana DUI cases include:

• The arresting officer's observations, such as red or bloodshot eyes, the smell of marijuana, slow or slurred speech, and unusual behavior

• Field sobriety test results, such as the walk and turn and the one-leg stand

• A Drug Recognition Expert evaluation, which is a structured examination conducted by a specially trained officer to identify signs of drug impairment

• Blood test results showing the presence of THC or its metabolites

• Statements made by the driver during the stop

Each of these pieces of evidence can also be challenged. Field sobriety tests are not perfectly reliable. Drug Recognition Expert evaluations involve a degree of subjectivity. And blood test results showing the presence of THC do not always mean the driver was actually impaired at the time of driving.

Does a Positive Blood Test for THC Prove Impairment in a DUI Case?

A positive blood test does not prove impairment, and this is one of the most important things to understand about marijuana DUI cases. THC, the active compound in marijuana, can remain in the bloodstream for days or even weeks after use, long after any impairing effects have worn off. A positive THC blood test shows that marijuana was used at some point, but it does not prove the driver was impaired when they got behind the wheel.

This is a meaningful distinction that skilled defense attorneys raise regularly in Tennessee marijuana DUI cases. The state still has to connect the presence of THC in the blood to actual impairment at the time of driving, and that connection is not always easy to make.

What Is a Drug Recognition Expert and Can Their Testimony Be Challenged?

A Drug Recognition Expert, or DRE, is a law enforcement officer who has received specialized training to identify signs of drug impairment in drivers. When a marijuana DUI is suspected, a DRE may be called to conduct a 12-step evaluation that includes checking vital signs, eye responses, muscle tone, and other physical indicators.

DRE testimony can be challenged in court. The evaluation process involves subjective judgment calls, and the officer's conclusions are only as reliable as their training and the accuracy of their observations. Defense attorneys can question whether the DRE followed proper protocol, whether there were alternative explanations for the physical signs that were observed, and whether the officer's conclusions are supported by scientific evidence.

Can You Be Charged With Marijuana DUI if You Have a Medical Card?

Tennessee does not have a medical marijuana program of its own, but some Tennessee residents hold valid medical marijuana cards from other states. Having a medical card does not protect you from a DUI charge in Tennessee. The law does not make an exception for medical use when it comes to impaired driving. If marijuana impaired your ability to drive, you can be charged regardless of why you used it or whether it was legally obtained elsewhere.

What Are the Penalties for a Marijuana DUI in Tennessee?

The penalties for a marijuana DUI in Tennessee are the same as for an alcohol DUI. A first offense under Tennessee Code Annotated § 55-10-403 carries a minimum of 48 hours in jail. However, you can face up to 11 months and 29 days. There is also a fine of between $350 and $1,500 and a one-year license revocation. Subsequent offenses bring longer jail terms, higher fines, and longer license revocations. A DUI conviction also results in a permanent criminal record that can affect employment, professional licenses, and other areas of your life.

Schedule a Free Consultation With Our Knox County, TN DUI Defense Attorney

A marijuana DUI conviction can have serious consequences, but the state's case is not always as strong as it looks on the surface. The Farragut, TN DUI defense lawyer at The Baker Law Firm is a Top 40 Under 40 attorney who brings focused, dedicated representation to people facing serious criminal charges. Call 865-200-4117 to talk about what happened during your stop and find out what your options are.