Marijuana in the Workplace: Clearing Away (at Least Some of) the Confusion

By Karen DiGioia, Herbein + Company Inc.

Marijuana. Possession and use remain federally illegal. However, as of June 2025, 38 states – including IA&B member states of Pennsylvania, Maryland, and Delaware, plus the District of Columbia – have comprehensive medical marijuana programs. Back in 2019 when this article was first published, that number was 33. Additionally, 24 states (up from 11 in 2019) plus the District of Columbia allow both recreational and medical marijuana, with several other states currently considering legalization. State laws continue to change quickly, so depending on when you’re reading this, some of these numbers may very well have changed again.

To some degree, we’ve learned to live with the ambiguity of the subject. However, if I’m totally honest, writing about this still makes me a bit nervous. The rapidly changing landscape and inconsistency between federal and state laws leaves many employers confused about what they can and can’t do when it comes to marijuana in the workplace. Even many HR professionals admit to finding it perplexing. While there’s much about this topic that is still hazy, and I don’t claim to have all the answers, I’m going to focus on what currently is clear and try to eliminate some of the confusion. To keep things simpler, I’ll focus primarily on the state of marijuana laws in Pennsylvania, Delaware, and Maryland.

Currently, all three states have medical marijuana programs that make it legal for an individual with a medical marijuana license to buy, possess, and use medically prescribed marijuana, just like it’s legal to buy, possess, and use other prescribed medication. Maryland and Delaware also have legalized recreational marijuana purchase, possession, and use for adults 21 and over. While most are clear that, from a recreational use standpoint, it’s not OK to come to work high (just like it’s not OK to come to work drunk), many employers are not as certain whether it’s OK for individuals with medical marijuana licenses to use marijuana in the workplace or to come to work high for medical reasons. I have good news for you – this is one area where the current answer is very clearly “No!” (Did I just hear a collective sigh of relief?)

As an employer, you can and should take several steps to make this murky topic clearer and to protect yourself and your agency:

1. Prohibit marijuana use while on the job.

Just like (I hope) you would prohibit an employee from keeping a bottle of vodka in their desk drawer or a bottle of wine in the office fridge and taking a sip from said bottle over the course of the workday, you can and should prohibit employees from using marijuana (medical or recreational) in the office. (I’m not even going to touch on the beer fridges that have popped up in some workplaces. As insurance professionals, I’m guessing that’s not happening in your office).

2. Understand that, with some limited exceptions, it's not okay to refuse to hire or to fire or discipline an employee strictly for the use of medical marijuana.

The key word in the statement above is “strictly.” As we’ll talk about in a moment, it’s fine to deal with impairment at work if it occurs, but it’s not OK to take action just because an employee has a medical marijuana license or uses medical marijuana. Several states, including Pennsylvania and Delaware (not Maryland), have employee protection laws in place that make it unlawful to fire or discipline an employee strictly because that employee is licensed to use medical marijuana, or to fire or discipline an employee with a medical marijuana license who tests positive for marijuana use in a drug test, unless failing to do so would cause the employer to lose a monetary or licensingrelated benefit under federal law or regulation.

For more detail regarding the current laws in each state, see below:

Pennsylvania: The Pennsylvania Medical Marijuana Act (MMA) prohibits employers from firing, threatening, refusing to hire, or otherwise discriminating against an employee based strictly (there’s that word again) on their status as a certified medical marijuana user. Employers, however, are not required to accommodate the use of medical marijuana on the premises and may discipline employees who are under the influence at work.

Additionally, employees with more than 10 nanograms of THC per milliliter of blood may not perform certain defined tasks where safety is a concern.

Delaware: Like Pennsylvania, the Delaware Medical Marijuana Act (DMMA) prohibits discrimination against employees based on their status as medical marijuana cardholders and similarly, employers are not required to accommodate the use of medical marijuana on the premises and may discipline employees who are under the influence at work. Delaware law does not provide protections for off-duty recreational marijuana use.

Maryland: Maryland's medical marijuana law does not explicitly prohibit employment discrimination based on medical marijuana use. Employers are permitted to maintain drug-free workplace policies and may take adverse actions against employees who test positive for marijuana, especially if not doing so would violate federal law or cost the employer federal benefits.

3. If an employee comes to work impaired, whether it's due to marijuana use (medical or otherwise), alcohol use, or use of prescribed (or unprescribed) medication, deal with the impairment as a performance issue, rather than focusing on the use of the substance.

This one’s pretty straightforward. If an employee had four beers for breakfast and came to work drunk, you’d handle this as a performance issue. The issue is not the use of alcohol; the issue is on-the-job impairment. Deal with marijuana the same way. Document the performance deficit in detail, focusing on the expected standards of performance. If possible, have signed statements from others who witnessed the behavior. If your policy is to test when impairment is suspected, drive the employee to the drug-testing facility (please, don’t have them driving themselves if you suspect that they are impaired). Meet with your employee, as you would with any other performance issue. Talk about the performance, the behavior and the related consequences. Consistently follow the policies that you have in place regarding both performance issues and substance use/abuse (more on that below).

4. Clearly communicate agency policy regarding workplace use of marijuana and other substances, the consequence of noncompliance, and the process that will be followed if non-compliance is suspected. Enforce your policy consistently.

As we’ve already recognized, this is a confusing subject – and that’s true for employers and employees alike. Don’t assume your employees understand what’s OK and what’s not. Employees may wrongly assume that if they can legally use marijuana, they can do so at work without consequences. It’s still OK for employers to implement drug-free workplace policies. Adopt a written policy regarding substance use and communicate it to your employees. Ensure that your policy prohibits both marijuana use in the workplace and impairment in the workplace and during work time. Ensure that you and your managers know how to identify marijuana impairment.

So far, I’ve primarily focused on the things that are clear. Now, I’m going to move on to an area that is less so: testing. Drug testing — especially pre-employment testing for drug use that includes marijuana — is a practice that is increasingly being questioned and reconsidered by many employers.

Employees covered by Department of Transportation rules — those in safety-sensitive jobs like trucking, airline, and mass transit work — must still be tested for alcohol and drug use. But what about organizations where testing isn’t mandated?

As marijuana legalization continues to evolve across the United States, employers are facing increasing pressure to update their drug testing policies, particularly concerning pre-employment marijuana screenings. Several states have existing laws that prohibit or restrict pre-employment drug testing for marijuana. Within our membership geography, Philadelphia is currently the only jurisdiction that – with limited exceptions – prohibits employers from requiring prospective employees to submit to marijuana drug testing as a condition of employment.

From a legal standpoint, restrictions on testing are still the exception, not the rule. However, many employers are nonetheless moving away from pre-employment drug testing. Quite honestly, it’s often because such testing screens out too many otherwise qualified candidates. In today’s highly competitive labor market, some employers are deciding that it just doesn’t make sense anymore. In states that have legalized recreational marijuana, the practice of making employment decisions based on tests that reveal marijuana use has become even murkier.

Add to all this the fact that testing for marijuana use is much different than testing for alcohol. Alcohol tests clearly show impairment and recent use. Marijuana testing is less clear. There’s no common level of THC that indicates that a person is impaired, and THC can show up in a test as many as 30 days or more after use. This means that a test can come back positive for THC, but this doesn’t mean that the employee was high at the time of the test. As a practice, the current shift, especially for positions where safety is not a concern or where testing is not mandated, is to discontinue pre-employment testing and utilize testing only when an employee appears impaired or when an accident has occurred. Many organizations are also shifting, whenever possible, to tests that measure performance impairment rather than the presence of THC in the employee’s system.

If your practice has been to conduct pre-employment tests, it’s a good time to give careful consideration to why you do it and ensure that you still feel that it is important. If you do decide to continue testing, review the type of test that you use and keep yourself updated on the legal state of this topic.

I’m hopeful that this article has helped to clear away some of the confusion around the topic of marijuana in the workplace (a girl can dream, can’t she?). However, it’s important to recognize that there are still murky areas and the evolution of this topic will continue. What’s true today may not be true tomorrow. Your best bet is to stay on top of the subject and, as always, if you have any questions or concerns, don’t hesitate to drop me an email (khdigioia@herbein.com) or give me a call at 484-465-1201.

Karen DiGioia provided this article on behalf of Herbein + Company, Inc., IA&B’s contracted human resources consulting firm.