Your state may be OK with you smoking pot, but that doesn't mean your employer is.

Two more states and Washington D.C. voted to legalize marijuana last week. That makes recreational marijuana legal in four states, while medical marijuana is legal in 21. Momentum is certainly building.

But only two of those 21 states have a law on the books that protects workers from getting fired for failing a drug test at work: Arizona and Delaware. And no state law protects recreational smokers.

So even though you can walk into a store and buy weed legally, you can still lose your job for smoking it. That's true even if you only smoke on personal time and always show up to work stone cold sober.

That's what Brandon Coats says happened to him. He's a quadriplegic who was fired by Dish Network (DISH) in 2010 for marijuana use. He got the OK to smoke medical marijuana from the state of Colorado, where medical use has been legal since 2000. He says that he never smoked the drug -- or was under the influence -- at work.

Related: Where pot is legal

The Dish Network doesn't disagree with these facts. But it has a zero-tolerance drug policy. Marijuana is still illegal on the federal level, regardless of what Colorado or any other state says.

That means that a Colorado employer that has a drug testing policy in place can fire employees who flunk one.

Coats sued the company and the case has moved up to the Colorado Supreme Court, which heard arguments in September but hasn't handed down a decision yet. Its decision will only apply to Colorado employers, but other states could face similar cases.

Most state laws either don't address the employer issue or say that companies don't have to accommodate the new state law, said CJ Griffin, an employment and labor attorney at Pashman Stein.

Policy is murky in a lot of places.

While some states, including New York, say employers can't fire you for being a medical marijuana patient, they don't say anything about what happens if you fail a drug test.

And no matter what the law says, it may not apply to workers in safety-sensitive jobs, like train conductors, who might not be protected by the law.