It is an absurd flaw that members of a large and state-sanctioned industry such as medical marijuana are forced to conduct business largely in cash.

Few other legitimate industries – and the highly regulated, $3 billion-a-year legal cannabis industry is certainly legitimate – would be allowed to suffer for long in such a peculiar way without legislative action. Yet attempts to fix the situation have so far stalled.

That delay has hurt countless business owners and health care providers, including many marijuana caregivers in Maine, who cannot fully rely on banking services because they deal with a product that federal law considers illegal.

Congress should move swiftly to pass legislation that ends this confusion, and gives financial institutions the unambiguous right to work with organizations that legally sell marijuana.

Right now, there is very little clarity or reliability in banking for Maine’s medical marijuana industry, which last year accounted for $60 million to $75 million in sales.

Marijuana may be legal as a prescribed medicine in Maine, but to the federal government it is still a Schedule 1 narcotic, in the same category as heroin and cocaine.

For federally chartered banks, taking the business of the state’s legal growers and dispensaries exposes them to risks, such as penalties for money laundering, that are not present with other businesses.

There have been efforts to work around the law. A statement by the Department of Justice declaring investigations of legal marijuana practices a low priority, however, did nothing to assuage banks. And alternatives, such as the creation of special credit unions or change through state legislation, have fallen short in Colorado, where recreational marijuana is legal.

Federal action is necessary to solve this problem. The Marijuana Businesses Access to Banking Act of 2015 would grant banks that deal with the marijuana industry immunity against federal prosecution, and it should be passed as soon as possible.

Until it is, marijuana businesses and organizations will be left in many cases unable to get a bank account. Others have found their accounts suddenly closed because their bank became skittish about federal legal exposure.

Medical Marijuana Caregivers of Maine, a trade organization that doesn’t grow, handle or sell the drug in any way, was dropped from its bank in 2013 just because its name includes the word “marijuana.”

The inconvenience is staggering. Businesses can’t take patients’ credit or debit cards, and they have to worry about disruptions in payroll. Caregivers, growers and retailers in some cases have to control large amounts of cash, a security risk that also makes it difficult to pay bills and taxes.

At the same time, the federal restrictions aren’t preventing fraud, money laundering or tax evasion, as they are supposed to do. If anything, because of the abundance of cash, they are making those crimes more likely.

They also won’t halt the rise of legalized marijuana, nor keep more people from using the drug.

The restrictions will only keep the marijuana industry from operating in the most safe, transparent way possible, and they should be nullified.