“But I have a medical marijuana card…” — yeah, that’s not a defense.

Mississippi’s legalization of medical marijuana under the Mississippi Medical Cannabis Act has created a quiet but growing legal issue that many people don’t fully understand.

A medical marijuana card may protect you from a possession charge. It does not protect you from a DUI.

That distinction matters, and it is already showing up in real cases across Mississippi.

The Law Focuses on Impairment, Not Legality of medical marijuana

In Mississippi, DUI law is built around one central question: were you impaired?

It does not matter whether the substance came from a dispensary, a pharmacy, or a liquor store. If an officer believes your ability to safely operate a vehicle is affected, you can be arrested and charged.

That means medical marijuana, even when lawfully obtained and properly used, can still form the basis of a DUI charge.

There is no “legal limit” for marijuana like there is with alcohol. There is no bright line number that tells you when you are over or under the limit. Instead, these cases are built on observations and interpretation.

Officers rely on behavior, speech, coordination, and performance on field sobriety tests. In some cases, there may be blood evidence, but THC levels do not correlate neatly with impairment the way alcohol does.

The result is a legal gray area where presence and impairment are not the same thing, but they are often treated that way in the moment.

The Tiger Woods Example

If this sounds theoretical, it is not.

Tiger Woods has been through multiple DUI cases where alcohol was not the issue. In one widely reported incident, he registered a 0.00 on a breath test and was still arrested after being found asleep behind the wheel of a running vehicle. The issue was not alcohol, but impairment linked to prescription medication.

In a more recent incident, he was involved in a crash that resulted in his vehicle rolling over. Again, alcohol was not the central issue. Officers focused on signs of impairment, and he refused a chemical test, which created its own legal consequences.

These cases highlight a simple but important principle: legality of the substance does not control the outcome. Impairment does.

Where People Get Into Trouble

The most common mistake I see is a false sense of security.

People assume that because they are using medical marijuana legally, they are insulated from criminal liability. They are not.

They assume that if they did not drink alcohol, they are safe. They are not.

They assume there must be some objective test or number that determines guilt. In most cases involving marijuana, there is not.

So what happens? Someone uses a legal substance, gets behind the wheel, and ends up in a situation where an officer makes a judgment call about impairment. From there, the case is built around that initial observation.

How These Cases Are Fought

From a defense perspective, these cases are rarely about a clear-cut violation. They are about interpretation.

Was the driver actually impaired, or did they simply have a substance in their system?

Were the field sobriety tests administered correctly?

Do the officer’s observations hold up under scrutiny?

Does the available evidence truly establish impairment beyond a reasonable doubt?

These are the fault lines where these cases are won and lost.

The Bottom Line

Medical marijuana is legal in Mississippi. Driving under the influence is not.

Those two truths can exist at the same time, and increasingly, they do.

As medical marijuana use becomes more common, DUI charges tied to lawful substances will become more common as well. That is the reality drivers need to understand, and it is the reality the legal system is now dealing with.

A Final Word

If you are using medical marijuana, you need to treat it the same way you would alcohol when it comes to driving. If there is any question about impairment, do not get behind the wheel.

And if you find yourself charged with DUI, understand this: these cases are not as straightforward as they may appear at first glance. They often turn on details that can be challenged, tested, and, in the right circumstances, beaten.

If you or someone you know is facing a DUI charge in Jackson, Brandon, Madison, or anywhere in Mississippi, The Yurtkuran Law Firm is available to help you understand your options and defend your case.

The difference between a conviction and a dismissal is often found in the details.