With at least 33 states permitting medical marijuana use in some form, most employers are sitting in states or likely have employees who work in states that permit its use. While each state has its own rules of medical marijuana use as it relates to employment, employers should be cautious about this issue and are well advised to become familiar with what their specific state or states permit and understand that the issue may not be as simply as just saying no. While each state has its own rules about medical marijuana use and most allow an employer to prohibit its use at or being under its influence while at work, for most that does not end the analysis. While some similarities exist, each state has its own rules as to who qualifies for it use and what forms may be used, for example some states permit it to be smoked while others do not. As a result, given the variations in state laws, employers who have employees in multiple states should carefully review each state law to ensure that any differences are taken into account in response to this issue. To further complicate this issue, some states have specific rules about certain types of professions or tasks in terms of medical marijuana use, which may require employers to create special rules for some groups of employees. For example, Pennsylvania sets a specific blood content level for employees who are in control of a public utility. To further complicate this issue, some states also include anti-discrimination provisions that provide protections for medical marijuana users. In those states, employers are prohibited from firing, refusing to hire someone, or taking any other type of adverse employment action simply because the employee qualifies for or uses medical marijuana, even if outside of work. Several courts in states that have these types of protections have found that an employee can sue their employee in court for violation of this type of provision, just as with any other type of anti-discrimination statute. Even in those states that do not have such protections, some courts have found that state disability anti-discrimination statutes provide protections to such employees, given that many of the conditions which qualify for the use of medical marijuana also qualify as disabilities under the ADA or applicable state law. The result of these findings is that employers cannot simply rely upon a drug test to show an employee is using marijuana at work, given that it may still be in their system from before they came to work, but rather may need to have other evidence to show impairment at work and likely cannot discipline for use of medical marijuana outside of work. In addition, several courts have suggested that where an employer requires drug testing, it must engage in the interactive process with employees who use medical marijuana to determine if reasonable accommodations need to be provided, which could include exempting the employee from drug testing or other accommodations. A final complication on this issue is that medical marijuana is still illegal under federal law, but that does not give employers the right to simply rely on federal law when addressing this issue. Rather most states have found that employers can only rely upon federal law if federal law directly prohibits the specific type of employee from using marijuana, such as requiring negative drugs tests. For example, airline pilots or other types of positions that are subject to federal licensing requirements and require drug testing as part of the position normally permit an employer to prohibit any marijuana use, even outside of work, if it will result in a positive drug test. However, the courts have been more reluctant to expand this to employers who do federal work or work under federal grants, finding that federal law does not require employers to not employee people who violate federal law themselves. For example, in one case a nursing home, which received federal money in grants, could not refuse to hire someone on the basis that they used medical marijuana outside of the work day. As a result, employers are well advised to carefully review what positions, if any, they have where employees are subject to drug testing under federal law and not rely upon the federal prohibition as a basis to discipline or refuse to hire all employees. With this background, employers should come up with a plan to respond to employees who may be using medical marijuana. First, while in most states employers do not have to permit its use at work, employers who want to do so should create clear guidelines for when it can be used and who can use it. Second, employers should be prepared to engage in the interactive process with employees who use this outside of work and even those who claim they are unable to do the job without their medical marijuana during the workday to determine what reasonable accommodations must be provided. Third, employers should review the positons in their company to determine if there are some positions that need to be subject to different rules under federal or state law due to the type of job involved. Finally, employers should be aware that this is an evolving area of the law and should stay informed of changes in the law at both the state and federal level on this issue and should consult with legal counsel when dealing with these issues at least until the law becomes more settled in this area.