Marijuana (THC) has undergone one of the biggest changes for illegal drugs in the past decade in the United States. As of May 2026, there are currently 25 states that have fully legalized THC, 21 with mixed laws, and only 5 states that deem it fully illegal. It is also undergoing a process that will transition it from a schedule 1 drug to a schedule 3 drug. Which begs the question, as a DOT regulated driver, am I still prohibited from consuming THC? Well, as of May 2026, the DOT has just answered that question.
The Short Answer.
Yes, the Department of Transportation still prohibits any DOT regulated employees from consuming any type of THC product (state regulated or not).
Medical Marijuana, is it not just Another Prescription?
Well, what if you get prescribed medical marijuana, can the MRO deem my test negative? No, currently there is no scenario that allows an MRO to verify a laboratory-confirmed marijuana positive drug test result as “negative”. Even if an employee claims the positive was caused by a State licensed marijuana product.
Even after rescheduling, state-dispensed marijuana does not make it an FDA-approved drug. A “legitimate medical explanation” requires use of a legally prescribed controlled substance in compliance with the Federal laws that govern that prescription.
Even if the MRO is presented with a legitimate “Medical Marijuana Card”, physician recommendations or certificates, or dispensary records & receipts, these documents will not satisfy part 40 requirements for a “legitimate medical explanation.”
Are DOT-regulated positions the only ones prohibited from consuming THC?
There are many non-DOT related positions that get tested as much as DOT-regulated positions. Typically, these fall into the safety sensitive category and are commonly tested for THC use. While not all companies are okay with THC use, we have seen a trend in non-DOT companies leaving THC off their drug panels. If you are in a safety sensitive position, or get tested regularly for drugs, we recommend not consuming THC just to be sure.
How long does Marijuana Stay in my System?
If you have recently consumed THC and are looking for new employment which might require a drug test, do you know the detection windows? Unfortunately, it is hard to give precise estimates for detection windows for any drug. There will always be external factors causing variance. Such as age, body weight, metabolism, frequency of use, etc. However, we can approximate based on the average. Typically, THC is detectable in saliva for 24 hours, in urine for 30+ days, and in hair for 90 days.
FAQs About Marijuana Use
Will smoking weed one time show up on a drug test?
Yes, using marijuana even just once will show up on a drug test.
Can inhaling secondhand marijuana smoke make me test positive for THC?
Inhaling secondhand smoke will rarely result in a positive on a drug test. It can introduce THC in your system, but it will likely never meet the standard detection threshold.
Will CBD products cause me to test positive for THC on a drug test?
Like secondhand smoke, consuming CBD introduces trace amounts of THC into your system. However, these trace amounts will likely not meet the detection threshold needed for a positive result.
Can employers still test for weed in legal states?
Yes, any employer reserves the right to enforce a drug free workplace. THC may be legal and decriminalized at the state level; however, it is still illegal at the federal level.
To learn how KT can help your company in the ever-changing workplace, check out our consortium services.