As more states legalize the sale and use of marijuana, questions continue to arise about whether drug testing protocols will change for DOT-regulated drivers. So far, 29 states in the U.S., along with Washington D.C., have approved the drug for medicinal and/or recreational use. So, if you’re a CMV driver living or working in a state that has legalized pot, does that mean you can enjoy a joint during your free time without any consequences? If you have a medical marijuana prescription, will you be allowed to have a positive result on your drug test? Keep reading to find out if the new state laws have changed anything for CDL drivers.

If marijuana is legal in my state, does that mean I’m allowed to use the drug recreationally when I’m off duty?
No, says the Department of Transportation. Marijuana is still illegal under federal law, meaning all “safety sensitive” employees who are subject to federally-mandated drug testing are still prohibited from using the drug. This group of employees includes anyone who operates commercial vehicles, including train engineers, pilots and school bus drivers.

The DOT has made its stance on the issue known multiple times, beginning when Washington and Colorado legalized recreational marijuana in 2012.

“We want to make it perfectly clear that the state initiatives will have no bearing on the Department of Transportation’s regulated drug testing program. The Department of Transportation’s Drug and Alcohol Testing Regulation – 49 CFR Part 40 – does not authorize the use of Schedule I drugs, including marijuana, for any reason,” the DOT said in a statement.

Because marijuana is classified as a Schedule I drug by the United States Controlled Substances Act, safety sensitive employees are not permitted to have it in their systems at any time. Even if you’re sober when you take a drug test, the THC from the drug will be detectable in your urine for up to 30 days after use. If you test positive for marijuana on the drug test, you will be removed from your job immediately and be required to work with a Substance Abuse Professional to complete the Return to Duty process.

What if I have a medical marijuana card from my doctor?
Even if you live in a state where marijuana is legal and you’ve been prescribed the drug for medical reasons, you are still prohibited under federal law to use the drug while employed as a CMV driver. You will still be required to take DOT-mandated drug tests and if you receive a positive marijuana test result, regardless of whether you have permission to use medical marijuana, you will be held accountable.

What if I refuse to take a drug test?
Refusing to take a drug test will be treated as if you received a positive result, according to the DOT. You will still be removed from your job and required to complete the Return to Duty process.