In a case which has been monitored by employers nationwide, the Colorado Supreme Court upheld an employer’s decision to terminate an employee for testing positive for tetrahydrocannabinol (THC), in a random drug test.

Brandon Coats is a quadriplegic and has been confined to a wheelchair since he was a teenager. Mr. Coats has a state-issued medical marijuana card that allows him to obtain marijuana for painful muscle spasms caused by his medical condition. According to Mr. Coats, he consumed medical marijuana in the privacy of his own home, and after work, but did not consume medical marijuana at work or come to work impaired.

Mr. Coats worked for Dish Network from 2007 to 2010 as a telephone customer service representative. In May 2010, Mr. Coats tested positive for THC, an active ingredient in marijuana in a random drug test. Coats informed Dish’s HR representatives that he was a registered medical marijuana patient and planned to continue using medical marijuana. On June 7, 2010, Dish fired Mr. Coats for violating the company’s substance abuse policy.

Mr. Coats filed a wrongful termination lawsuit against Dish under Colorado’s Unlawful Prohibition of Legal Activities as a Condition of Employment Act, Colo. Rev. Stat. § 24-34-402.5(1) (hereinafter “Lawful Activities Act”). He claimed that Dish violated this statute by firing him based on his off-duty, off-premises use of medical marijuana. He argued that his use of medical marijuana was “lawful” under Colorado’s Medical Marijuana Amendment and its enabling legislation.

Dish argued that Mr. Coat’s medical use of marijuana was not “lawful” for purposes of the statute because use of even medical marijuana is illegal under federal law. The trial court dismissed Mr. Coat’s claim. It rejected his argument that the Medical Marijuana Amendment made his use a “lawful activity” for purposes of the Lawful Activities Act.

On appeal, the parties submitted the same issues. In a split-decision, the Colorado Court of Appeals held that to be “lawful” for purposes of the Lawful Activities Act, the activities must “be permitted by, and not contrary, to both state and federal law.”

The Colorado Supreme Court affirmed the Court of Appeals decision in a 6-0 [1] ruling, specifically holding that the term “lawful” as used by the Lawful Activities Act “is not restricted in any way, and we decline to engraft a state law limitation onto the term. Therefore, an activity such as medical marijuana use that is unlawful under federal law is not a ‘lawful’ activity under [the Lawful Activities Act].” The Court went on to hold that the state legislature did not intend to extend the Lawful Activities Act protection for “lawful” activities to activities that are unlawful under federal law.

This decision is good news for Colorado employers that have zero tolerance substance abuse policies and it does not require employers to guess or speculate whether an employee is still under the influence of THC, if he or she tests positive for marijuana.

* Justice Marquez did not participate in the decision.