As both medical and recreational marijuana laws continue to increase in numbers across the nation, employers should be aware of a few significant ways medical marijuana is affecting their employees. First, all marijuana is still considered illegal under federal law and its use during work hours is a cause for termination, but many judges across the country are placing medical marijuana in the same category as other lawful prescription medications. In addition, it is difficult to test for marijuana impairment and employers, instead, look to other kinds of evidence, such as poor performance and on-the-job accidents. Employers can respond by being both proactive and prepared, working with a legal team to create a comprehensive workplace drug policy, and making sure it remains clear and up-to-date.