Last updated : May 12, 2025
Medical marijuana is now “legal” in 18 states with Washington, Colorado, and the District of Columbia allowing some form of recreational use. While you may think you’re clear of trouble if you choose to use “legal” marijuana, it may not be as safe as you think; your employer still has the right to fire you!
Zero-tolerance drug policies are common with many employers and courts have repeatedly upheld the right of a business owner to test employees for illegal drugs. Don’t forget: while many states have given the green light on marijuana use, it remains an illegal drug under federal law. State laws may vary but it’s important to understand the potential consequences of using marijuana because it can show up in your system weeks later.
Medical use
In most cases, you will not be protected if you test positive for marijuana, even if you are using it “legally” under your state’s medical marijuana laws. That’s because state courts usually rely on federal pre-emption, which means that federal law (which bans all marijuana use) trumps state law approving it.
In many states with medical marijuana laws, such as Oregon and California, the courts have upheld an employer’s right to fire an employee for testing positive for marijuana, even if the employee wasn’t impaired. Some states have laws restricting firing an employee who uses medical marijuana unless they were found to be impaired on the job, although this is no guarantee a court will side in your favor.
In Colorado, “legal” use includes both recreational and medical use. In June, the Colorado Supreme Court ruled it legal for an employer to fire an employee who tested positive for marijuana and who had a prescription from a doctor. In that case, the court ruled that Dish Network was within its rights to fire Brandon Coats in 2010 after he tested positive for marijuana. Coats had been prescribed marijuana to treat muscle spasms and seizures. While Dish Network said that Coats was not smoking on the job or impaired, the court found it within its rights to stand behind its zero-tolerance drug policy.
Recreational use
Courts have repeatedly upheld that federal laws trump state laws. While your state may have approved recreational marijuana, remember it only protects you from being prosecuted under your state’s drug laws. Marijuana is still illegal on a federal level, whether it is used “legally” either medicinally or recreationally under your state’s laws. Employers still have the right to test employees for drugs illegal under federal law as well as terminate employees who test positive for marijuana, even if you aren’t impaired on the job.
You can be fired!
Courts in at least two states with “legal” medical marijuana—Oregon and California—have already ruled against employees who were fired for using marijuana with written authorization from a doctor. The bottom line? Using under marijuana “legally” in your state doesn’t protect you from federal laws and it won’t protect you from being terminated from your job under your employer’s drug policies. Yes, your employer can (and very well may!) fire you if they have a zero-tolerance policy, so you may want to think twice before you celebrate.
