Can I Be Fired for Smoking Marijuana in Colorado?

Colorado was one of the first states to legalize recreational marijuana. Many workers assume this means they cannot be fired for using it. But marijuana remains a tricky issue in employment law.

The short answer is yes—you can still lose your job for using marijuana, even in Colorado. This article explains why.

Marijuana Is Legal in Colorado, But Not at Work

While Colorado law allows adults over 21 to buy and use marijuana, the law does not force employers to permit its use.

Employers still have the right to maintain drug-free workplace policies. That means you can legally smoke marijuana on your own time, but your employer can also legally fire you if you test positive or violate company policy.

Why Federal Law Still Matters

Even though Colorado legalized marijuana, federal law has not. Under the federal Controlled Substances Act, marijuana remains classified as a Schedule I drug.

Because of this, employers that are subject to federal regulations, such as those in transportation or defense, must prohibit marijuana use.

Companies that receive federal contracts or grants are also required to maintain drug-free workplaces.

In addition, courts in Colorado have ruled that marijuana use is not considered a "lawful activity" under state law if it is still illegal under federal law. This means that even if you never use marijuana on the job, an employer may still terminate you for off-duty use if it violates company policy.

Workplace Drug Testing in Colorado

Employers in Colorado are generally free to require drug testing. While some states limit when and how drug testing can occur, Colorado law does not restrict it much. Common situations where testing may happen include:

• pre-employment screenings
• random testing under company policy
• post-accident testing, and
• testing based on reasonable suspicion

If you fail a drug test, you may face discipline or termination, even if your marijuana use was legal under state law and off-duty.

What About Medical Marijuana?

Colorado also legalized medical marijuana before recreational use. Some workers believe that having a medical marijuana card protects them from firing, but the Colorado Supreme Court has ruled otherwise.

In a case involving a quadriplegic worker who used medical marijuana off-duty, the court held that his termination was lawful. The reasoning was that because marijuana is still illegal under federal law, it is not protected as a lawful off-duty activity under state law.

So whether marijuana use is recreational or medical, employers may still take adverse action.

Employer Policies and Zero Tolerance Rules

Most Colorado employers have written policies on drug use, and some of these policies include zero tolerance rules stating that any positive test will result in termination.

Employers often adopt such policies to protect workplace safety, comply with federal requirements, and maintain productivity and attendance standards. Some employers might be more flexible, especially as workplace attitudes toward marijuana shift. However, the law still gives them the right to enforce stricter policies.

The Future of Marijuana and Employment Law

The legal landscape is evolving. As more states legalize marijuana and public opinion shifts, some employers are rethinking strict policies. Several states now prohibit employers from firing workers for off-duty marijuana use, as long as they are not impaired on the job. Colorado has not yet passed such a law, but future changes are possible.

Next Steps

If you are facing discipline or termination for marijuana use, review your employer's policies carefully. You may need to consult an employment lawyer if you believe your employer applied its policies inconsistently. A lawyer can explain your rights, review your case, and help you decide on your next move.