Now that most U.S. states have legalized medical uses for marijuana and 19 allow recreational use, questions are arising about whether workers’ compensation systems should cover medical marijuana costs.

Minnesota became the most recent state to weigh in with an answer on Oct. 13, when the state’s supreme court ruled that the state’s workers’ comp system does not cover medical marijuana.

The court issued a pair of rulings overturning decisions by the state’s Workers’ Compensation Court of Appeals that ordered employers to pay for the medical cannabis used by two workers who were injured on the job.

Federal Law Preempts the State, Minnesota Says

Although Minnesota does allow the medical use of marijuana, regulating it through the state health department, the justices said that it does not extend to workers’ comp because pot is still illegal under federal law.

The court concluded that the federal prohibition of marijuana under the Controlled Substances Act (CSA) preempts any order under Minnesota’s workers’ compensation law requiring an employer to reimburse an injured employee for the cost of medical cannabis.

Writing for the majority, Associate Justice G. Barry Anderson said the proper remedy is for Congress to pass legislation to resolve the conflict between state and federal laws.

“As it is impossible to comply with both state and federal law,” Anderson concluded, “the compensation court’s order is preempted by the CSA.”

How Other States Are Ruling

A review of legislative and court activity in this area shows that lawmakers and judges are not in agreement on whether medical cannabis should be covered by workers’ comp.

A recent report in the American Journal of Industrial Medicine (AJIM) looked at the 36 states that allow medical marijuana and found that five of them expressly allow workers’ compensation coverage for cannabis and seven expressly prohibited it. In 10 states, the law is silent on the issue, and in 14, insurers are “not required” to reimburse employees who were injured on the job (but, presumably, may reimburse) for costs related to medical cannabis.

Movement Toward State Acceptance

However, there appears to be a recent trend toward greater acceptance of workers’ comp reimbursements for medical marijuana. Of the five states that allow it, three of them — New Hampshire, New Jersey, and New York — joined the list earlier this year after supreme court and appellate court rulings in those states.

The authors of the AJIM study said they expected the number of states permitting cannabis-related compensation for workplace injuries to increase in the coming years “as more workers petition state courts and administrative agencies for cannabis … reimbursement.”

And as the justices’ reasoning in the Minnesota Supreme Court case makes clear, full legalization of pot at the federal level could make the issue moot.