In less than a month, Californians will be able to legally buy weed just for fun.

While recreational marijuana usage has been legal in the Golden State throughout 2017, the sale of non-medical marijuana was still against the law. That's changing on Jan. 1, 2018.

And though California's cannabis industry is still facing some speed bumps, bringing the  currently-underground recreational market into the light of day means more customers and more money. A study from University of California Agricultural Issues Center at UC-Davis estimated the state's recreational marijuana sales could reach $5 billion a year.

It's an expansion that could turn small companies into big ones—ones that need full in-house legal departments, a cannabis industry rarity today.

“As companies get bigger, then people may see the need for a GC,” said Burke Hansen, a San Francisco-based cannabis attorney at Hallinan and Hallinan. “The way it works now is most businesses have a regular attorney they work with but not a formal in-house counsel relationship.”

That's the relationship Nicole Howell Neubert, a principal at Clark Neubert, has with a few cannabis companies. She's been on the legal side of the cannabis industry for years, and she guides companies on everything from general corporate issues, including financing and structuring, to marijuana-specific regulations. In the months leading up to 2018, she's also worked with cannabis companies of all sizes to secure local permits necessary to apply to sell recreational marijuana.

Companies are also prepping for the new licensing fee structure for marijuana in the state. Fees depend on the company's size and purpose. Companies that transport marijuana and don't need to quality test the product they deliver would only pay $500. But the largest distributors, which do have to test, would pay $125,000 annually to stay licensed.

A growing market also means more deals, and cannabis companies in California may need more legal firepower to carry out mergers and acquisitions.

Neubert says that as the industry grows from small and niche to large and becomes relatively accessible to adult consumers, cannabis companies will begin to look more like regular businesses, potentially with the in-house lawyers to match. A background in cannabis law may be helpful, but attorneys looking to go in-house at a marijuana company mostly need the same skills as they would in any other industry.

“These businesses, like all other businesses, need lawyers of all practice areas,” she said. “They need good litigators, they need estate planners and they need good corporate counsel. On some basic level these are just businesses. They've had to exist in this nonprofit land and haven't been a traditional business until now. But they will be very much so next year, with opportunities for all kinds of attorneys who aren't [cannabis] specialists.”

Still, smaller and midsized cannabis companies may stick with the current outside general counsel model, at least for the moment. Neubert says developing an in-house team may not yet be financially viable for these players. But that doesn't mean lawyers shouldn't be paying attention to the growing industry and their potential role in it.

“I would encourage folks interested in entering the industry to focus on their specialist area,” Neubert said. “Focus on your strengths because the businesses need really good lawyers of all practice areas.”