In a move that could have major impacts for how employers treat marijuana use by workers, the Colorado Supreme Court on Monday announced it will review the case of a fired medical marijuana patient.

The patient, a quadriplegic man named Brandon Coats, lost his job for using marijuana off the clock. But, in taking up the case, the Supreme Court announced it would look not just at whether a special Colorado law that protects legal off-the-clock activities covers marijuana. For the first time, the court announced it will also look at whether Colorado’s constitution gives medical marijuana patients a right to cannabis.

Colorado’s Court of Appeals has previously ruled that patients don’t have a right to use marijuana and that employers can fire workers for any marijuana use.

“This is a big deal,” said Vance Knapp, a Denver lawyer who specializes in employment issues. “If the Supreme Court were to reverse, that would send major ripples through the business community in Colorado. There are multiple employers who have zero-tolerance policies.”

Because the questions are so similar, the Supreme Court ruling in Coats’ case would also have implications for recreational marijuana use. But Knapp said Colorado’s constitutional provision legalizing recreational marijuana has slightly different wording than the medical marijuana provision, meaning the case’s ripples only go so far.

Sam Kamin, a University of Denver law professor, said a Colorado Supreme Court ruling also won’t settle the national debate over state-legal marijuana use and employment. But, in a state that has become the country’s foremost marijuana-policy petri dish, Kamin said the eventual decision will draw national attention.

“It’s an issue that’s going to recur, and the Supreme Court wanted to make sure we had an answer to it,” Kamin said.

Coats was a telephone operator at Dish Network when he was fired in 2010 after he tested positive for marijuana. There was no allegation that Coats was stoned on the job, and his attorney said Coats had an exemplary employment record.

Instead, Dish Network said company policy prohibits employees from using marijuana — even if it is legal under Colorado law and done off-duty. Coats challenged his dismissal under the state’s Lawful Activities Statute, the law preventing employers from firing workers for doing legal things in their off-hours.

The Colorado Court of Appeals upheld Coats’ firing in a divided decision last April, reasoning that things that are illegal under federal law — like marijuana use — can’t be considered “lawful.”

In 2011, the Court of Appeals ruled in a different case involving a fired worker that medical marijuana patients don’t have a right to marijuana. The Supreme Court declined to review that case — a sign that it agreed with the ruling. But, in its announcement Monday, the state’s highest court said it would make a full review of both issues.

The move was cheered by marijuana advocates, who said the Supreme Court might be more inclined to give protection to marijuana users after Colorado voters endorsed marijuana legalization in 2012.

“We’re excited by the prospect of the Supreme Court having a more reasonable take on this issue,” said advocate Brian Vicente.

But Curtis Graves, a staff attorney for the Mountain States Employers Council, said the Supreme Court might also choose to affirm more strongly the Appeals Court’s decisions, cementing the current status quo.

If the Supreme Court did reverse the lower court’s rulings, employers would be forced to determine whether workers’ marijuana use is impacting their job performance before firing them. Graves said that would be difficult because currently only a blood test can show active marijuana levels.

“It would be much easier if we had a drug test that showed present impairment,” Graves said. “But it’s not that easy.”

Lawyer Knapp said the Supreme Court probably won’t hear oral arguments on Coats’ case until the summer, with a decision issued later in the summer or early in the fall.

John Ingold: 303-954-1068, jingold@denverpost.com or twitter.com/john_ingold