Your client calls and asks if she can fire (or not hire) an employee who tested positive for marijuana following the company’s routine drug test. Despite the growing popularity of cannabis stocks, you know that marijuana is still illegal under federal law, so you may assume the answer is: yes, an employer should be within its rights to fire an employee using an illegal drug in violation of the company’s zero tolerance, drug free workplace policy. However, a recent court decision and a change in New Jersey’s medical marijuana law should make you pause and provide your client with more nuanced advice.

For many years, employers and courts concluded that marijuana use (including medical marijuana) is illegal under federal law, so employers could continue with their zero tolerance policies. California was the first state to authorize medical marijuana, and it did not provide any employment law protections for medical marijuana patients. Over a decade ago, the California Supreme Court in Ross v. RagingWire Telecommunications,174 P.3d 200 (Cal. 2008), concluded that nothing in the medical marijuana statute required employers to accommodate medical marijuana use.