While it's still controversial, medical marijuana is edging toward normality. Forty states (and the District of Columbia) now have some form of law on the books that allow the drug to be used for a variety of ailments, and sales are soaring— reaching $5.4 billion in 2015.

That doesn't mean it's widely available in all of those states, of course. Some, like Alabama and South Carolina, have extremely strict circumstances under which cannabidiol products can be prescribed, and still forbid the production and distribution of the drug. And even in states where it's easier to come by, there are differences in how it's handled.

Americans for Safe Access Foundation, which lobbies for safe, legal access to cannabis for therapeutic use and research,came out in January with its annual state medical marijuana program rankings. Each state is scored on a wide variety of criteria, including patient rights and civil protection for users, access to the drug, cultivation, product safety and qualifying medical conditions.

No state achieved a grade of "A," but 10 earned a "B" or "B+":