November 01, 2015

How Medical Marijuana Laws Affect Employers

Todd A. Newman

Off-duty marijuana use by employees under state “medical marijuana” laws is on the rise. Although such activity may be lawful under state law, it remains unlawful under federal law, causing considerable confusion. This article helps clear the air.

State Law

Medical marijuana laws are on the books in 23 states and the District of Columbia. The states allowing marijuana use and possession for medical purposes are Alaska, Arizona, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, Montana, Nevada, New Hampshire, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, and Washington.

Federal Law

Federal law, however, continues to criminalize marijuana. Marijuana remains classified as a Schedule I substance under the federal Controlled Substances Act. Schedule I substances are deemed to have a high potential for abuse and no accepted medical use. As such, marijuana possession, sale, and cultivation are federal offenses.

Another federal law, the Drug Free Workplace Act, requires federal contractors to maintain policies and practices intended to achieve a drug-free workplace. Penalties for violating this law include suspension of payments under federal contracts, suspension or termination of federal contracts, and being barred from future federal contracts for up to five years.

Other federal laws prohibit marijuana use in the private sector. For instance, guidelines of the U.S. Department of Transportation (DOT) state: “It remains unacceptable for any safety‐sensitive employee subject to drug testing under the Department of Transportation’s drug testing regulations to use marijuana,” even medical marijuana under a state law.

Federal Preemption

When state and federal laws conflict, federal law generally controls—a principle known as “federal preemption.” Thus, an individual using marijuana under a state’s medical marijuana law may nonetheless be prosecuted by federal authorities for violating federal law. As noted, employers permitting marijuana use at work may face related risks.

Case Trends

Various employers have been sued after firing an employee for marijuana use. Some employers have gotten their case dismissed on the ground that marijuana use violates federal law. Others have prevailed on the argument that the state medical marijuana law at issue does not regulate private employment actions. For instance:

  • The Colorado Supreme Court upheld the termination of a quadriplegic employee for using marijuana, even though his drug use complied with Colorado’s medical marijuana law, because marijuana is illegal under federal law.
  • The Oregon Supreme Court upheld the termination of an employee for using marijuana to alleviate a debilitating medical condition, even though his drug use complied with Oregon’s medical marijuana law, because marijuana is illegal under federal law.
  • The U.S. Court of Appeals for the Sixth Circuit, which covers Kentucky, Michigan, Ohio, and Tennessee, upheld the termination of an employee who failed a drug test after using marijuana for pain associated with cancer, even though his drug use complied with Michigan’s medical marijuana law, on finding that the Michigan law did not regulate private employment actions.


It is difficult to predict whether, in such cases, the initial trend in favor of employers will hold. A change in federal law to permit marijuana use for medical purposes could affect employers’ obligations dramatically. Even absent such a change, this area of the law remains largely undeveloped, and courts in other jurisdictions may see the issues differently. In this regard, the first such case in Massachusetts has now been filed and should be watched closely.

Recommendations for Employers

In light of the growing ranks of employees using marijuana for medical purposes, employers should consider the following measures:

  • adopt policies prohibiting marijuana use in the workplace and providing for appropriate drug testing of applicants and employees;
  • if policies concerning drug testing and use already exist, then revise them, if necessary, to specifically address medical marijuana;
  • on learning of potential marijuana use by an employee, immediately determine if a federal law, such as the Drug Free Workplace Act or DOT regulations, requires certain actions to be taken; and
  • carefully assess all risks associated with allowing employee marijuana use, including, without limitation, those associated with legal liability, safety, productivity, workplace precedent, and public relations.

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As this is a dynamic and politically charged area of the law, employers should consult with experienced employment counsel when confronted with alleged “medical marijuana” use by employees.


Todd A. Newman

Todd A. Newman is a business, labor, employment, and litigation lawyer. His firm is located north of Boston in Salisbury, Massachusetts. Please visit for more detail and contact information.