December 8, 2022 2 min read

Amendment 3: What Employers Need to Know

As Amendment 3 ushers in the legalization of recreational marijuana in Missouri, employers around the state are faced with a host of questions. How will the new law affect workplace drug policies? Are there different workplace requirements for medical marijuana vs. recreational marijuana? Can an employer still test for marijuana impairment?

Over the next several weeks, the Missouri Chamber of Commerce and Industry will provide various Amendment 3 resources for employers. In the meantime, here are a few key issues that business owners should keep in mind as the new law goes into effect.

Can employers maintain drug-free workplaces?

The most important takeaway for business owners as we consider the implications of Amendment 3: employers may still maintain a drug-free workplace, which includes prohibiting employees from working while under the influence of marijuana.

The section of Amendment 3 that allows for recreational marijuana use clearly states that the section is not intended to allow for the use of marijuana in the workplace. The section later includes a provision that allows employers to discipline, discharge, refuse to hire or otherwise take adverse employment action against a person who works while under the influence of marijuana. Employers may enforce a zero-tolerance policy for employees and prospective employees who test positive for recreational marijuana use.

Are there new implications for medical marijuana cardholder employees?

While the discussion on recreational marijuana in the workplace is fairly straightforward, medical marijuana is more complex. Amendment 3 prohibits discrimination against medical marijuana cardholders, whether an employee is a cardholder themself or the employee serves as a primary caregiver. This protection extends not only to cardholders who are current employees, but also to prospective employee cardholders who are applying for a job. Put simply, a medical marijuana cardholder may not be refused employment or terminated by their employer solely because they are a cardholder.

It’s important to note that these protections do not prevent an employer from firing a medical marijuana cardholder if the cardholder was under the influence of marijuana in the workplace or during the hours of employment. While a cardholding employee testing positive for legal medical marijuana use outside of working hours is not grounds for termination by itself, an employer may take action against a cardholder if their medical marijuana use affects their ability to perform their job duties or puts others in the workplace at risk.

What happens if my business is subject to federal drug testing requirements?

Please keep in mind that Amendment 3 does not impact any drug testing requirements established by federal law. Most federal contractors and all federal grantees are required by law to establish and maintain a drug-free workplace policy.

The Missouri Chamber has partnered with Husch Blackwell to provide a webinar free of charge to our members on Jan. 13, 2023, at 10 a.m. During this webinar, the Husch Blackwell team will provide an overview of Amendment 3 and discuss how the new changes may affect workplace policies. The webinar will also include time for a Q&A session for attendees to ask questions. You can register for the webinar at

The full text of Amendment 3 can be found here. If you have questions about Amendment 3, please contact Heidi Geisbuhler Sutherland, the Missouri Chamber’s Director of Legislative Affairs, at


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