By: Joshua Stegeman and Jade Koller


In Missouri, how should employers handle employees with pre-existing medical conditions who are using legally prescribed medical marijuana? Second, how should an insurer handle an injured employee who has been legally prescribed medical marijuana for treatment within a workers’ compensation claim?


After the November 6th, 2018 election, a majority (65.54%) of Missouri voters voted “yes” for Amendment 2 to the Missouri Constitution. Amendment 2 became effective on December 6, 2018. At this time the state of Missouri still wading through process of approving Amendment 2 effectively allows for the limited legal production, distribution, sale and purchase of marijuana for medical use at the state level. This is not intended to change the current civil and criminal laws governing the use of marijuana for nonmedical purpose, and further, there is no intention to change the current Federal law, 21 U.S.C.A. § 812(c) governing marijuana as a recognized controlled substance. The impact on workers’ compensation is minor, because an employer can still enforce its’ reasonably adopted rules or drug-free policies, such as: prohibiting employees from coming to work under the influence, prohibiting employees from consuming the substance while on the job, and administering drug tests.

According to Missouri’s Department of Health and Human Services (DHSS) timeline, on January 5, 2019, they began accepting pre-filed applications and set up the Missouri Veterans’ Health and Care Fund at the state treasury. On May 24, 2019, the DHSS published final rules governing almost every aspect of the medical marijuana industry in Missouri, before the constitutional deadline of June 4, 2019.  On July 4, 2019, DHSS will begin accepting patients’ and providers’ applications for a medical marijuana license. On August 3, 2019, DHSS is set to begin accepting facility license applications, which Amendment 2 compels the department to allow at least 192 dispensary licenses, 61 cultivation licenses, and 82 infused-product manufacturer licenses. Lastly, December 31, 2019, is the deadline for approval of the August 3rd applications.

Since regulations related to the law are still being developed and determinations and rulings regarding the law and potential regulations have yet to be made, it remains to be seen how Missouri will handle certain issues surrounding medical marijuana.  Other states that permit use of medical marijuana have enacted statutes and regulations which permit the following:

  • Workers’ Compensation coverage of medically prescribed marijuana
  • Prohibition against discrimination in employment based on use or nonuse of marijuana products off the employer’s premises during nonworking hours. In other words, employers may not discriminate against employees who use medical marijuana while not on the job.
  • Employer drug policies cannot apply to the lawful use of medical marijuana outside the workplace.
  • Employers may have policies consistent with the law in Missouri, which prohibit employees from showing up under the influence of medical marijuana at work.

Missouri tends to be a conservative state in its approach to these types of issues, so it can be surmised that Missouri will lean toward statutes, regulations, and policies that limit the use and protections of medical marijuana in the employment setting.  With that said, we discuss the application of Missouri’s current workers’ compensation statutes pertaining to drug offenses more extensively below and how they would be impacted by medical marijuana.

Impact on Workers’ Compensation

Since, the Labor and Industrial Relations Commission in Missouri has not yet ruled on this issue, because there has not been an opportunity for a dispute to arise, it is difficult to know how it will impact Missouri workers’ compensation claims.

There are two likely outcomes for an employee’s use of medical marijuana as related to the workplace: (1) the medical marijuana is covered under an employer’s reasonably adopted rule governing workplace safety and therefore, the compensation and/or death benefit can be reduced by at least 25% or up to 50%, under Section 287.120.5 RSMo, or the more likely possibility is under Section 287.120.6 RSMo, since it involves the use of a controlled substance (2) the medical marijuana is covered under an employer’s drug-free policy and therefore, the compensation and death benefits can be reduced by 50% with a showing that the injury was sustained in conjunction with the use of alcohol or drugs under Section 287.120.6 RSMo.  An employee having a valid prescription for marijuana presents obstacles, however, due to the difficulty in assessing whether the employee was under the influence of marijuana at the time of the accident. If post injury drug testing was conducted that indicated marijuana was in the employee’s system, it would be very hard for the employer to pinpoint whether it was used by the employee while at work, and prior to the injury. As such, it would require the employer to obtain expert testimony about the level of marijuana in the employee’s system to opine if the level was sufficient to establish that the use of marijuana caused the work accident.  The employer could further prove the injury was sustained in conjunction with the use of marijuana, by identifying witnesses who saw the employee consume the marijuana shortly prior to the work accident, or who could testify that the employee was acting different or unusual than the employee might otherwise normally act before the work accident.

Drug-Free Workplace Violation – Section 287.120.6

Section 287.120.6(1) RSMo, states that “[w]here the employee fails to obey any rule or policy adopted by the employer relating to a drug-free workplace or the use of alcohol or nonprescribed controlled drugs in the workplace, the compensation and death benefit provided for herein shall be reduced fifty percent if the injury was sustained in conjunction with the use of alcohol or nonprescribed controlled drugs.”

Essentially if the Employee tested positive for drugs which was against the employer’s policies, then the employer shall reduce all benefits, including TTD benefits by 50%. Therefore, at the very least the employer can pay the employee only 50% of the benefits to which he may be entitled under subparagraph (1) if there is a positive test.  One could argue this would include medical marijuana if the employers’ policy indicates that employees are prohibited from presenting at work under the influence of drugs.  The policy could be revised to make it clear this would include the use of medically prescribed marijuana.  In essence the employer is not barring the employee from using medically marijuana, but rather prohibiting the employer from being under the effects of it while working.

But under  paragraph (2), it provides for a complete bar of benefits “[i]f, however, the use of alcohol or non-prescribed controlled drugs in violation of the employer’s rule or policy is the proximate cause of the injury, then the benefits or compensation otherwise payable under this chapter for death or disability shall be forfeited.”

Additionally, under paragraph  (4), which was revised by the legislature in August 2017, and stated that a positive test creates a rebuttable presumption as described by the following statutory language: “Any positive test result for a non-prescribed controlled drug or the metabolites of such drug from an employee shall give rise to a rebuttable presumption, which may be rebutted by a preponderance of evidence, that the tested non-prescribed controlled drug was in the employee’s system at the time of the accident or injury and that the injury was sustained in conjunction with the use of the tested non-prescribed controlled drug if:”

As indicated above, if the employer can show that the Employee’s use of the drugs was the PROXIMATE CAUSE of the work accident, then all benefits shall be forfeited pursuant to subparagraph (2).  The employer must prove proximate cause, UNLESS it has adhered to the elements defined in subparagraph (4).  Under that section, if the employer has:

1) Administered the test within 24 hours of the accident;

2) Provided the test results to the Employee within 14 days of receipt of the results;

3) The Employee was given a chance to have a 2nd test done (requires preservation of sample); and

4) The test results were confirmed by mass spectrometry

THEN, and only then is there a rebuttable presumption that the drugs were the PROXIMATE CAUSE of the work accident and the Employee must prove the drugs did not cause the accident.  However, the employer can only receive this benefit if these criteria are met.  Otherwise if employer did not follow this criterion, then it is the employer’s burden to prove proximate cause.


Because medical marijuana so recently became legal in Missouri, we must look to other states to help determine how it may impact workers’ compensation laws. An Illinois case that helps illustrate how it may be treated in Missouri is Wolfson v. Solar Wind USA, LLC, 14 I.W.C.C. 0438, 14 (Ill. Indus. Comm’n 2014).  In Wolfson, the Commission found, even though there was a drug test performed the day after the injury that returned a positive result, it was not enough to reduce compensation for [the employee’s] injury. The petitioner presented the evidence that he was sober and alert at the time of the injury because he was able to lift the solar panel over his head in an effort to prevent it from hitting the ground and shattering, which could have caused much more serious injury to him. Further, he had the medical marijuana on hand from a prior knee injury, and smoked it the night after the injury. The Commission found that the petitioner presented sufficient evidence at this point to rebut the presumption of his intoxication at the time of the incident. Id. Of course, the laws in Illinois concerning intoxication and drug use have a different burden of proof and penalties and those are more thoroughly discussed in the accompanying Illinois memorandum on this topic.

Medical marijuana is more in line with a prescribed drug than alcohol, because the prescribed drug has a therapeutic use, whereas alcohol does not. Medical marijuana would likely be treated by an employer similarly to a prescribed muscle relaxer: although it is legally being used, an employer may limit use during working hours if it has the potential to impair an employee and thus create a safety risk in the workplace.

Practice Tip

We recommend that employers prepare for the inevitable conflict between their reasonably adopted rules or drug-free workplace policies, and have potential solutions. An employer may wish to revise the drug-free workplace policy to specifically include language about medical marijuana and that an employee may not be under its influence during working hour, otherwise it will still be considered a violation of the drug-free work place policy.  In addition, employers should consider policies and whether they potentially discriminate against employees for use of medical marijuana and whether accommodations should be made for the same.  Employers will need to consider whether they will cover medical marijuana as part of medications under the group health plans offered to employees.  Employers should take note that some conditions medical marijuana may be prescribed to treat may be protected under the ADA. Potential conflicts between protecting the rights of those with disabilities and the legality of a once illicit substance will cause issues in advising employers on policies. In all likelihood, the safest way to treat medical marijuana is the same as any other prescription drug that has the possibility to impair its users.

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