Hoffman’s outreach comes as the Medford-based Century Bank, which has worked with medical marijuana dispensaries in Massachusetts since 2012, announced Thursday they won’t offer the same services to recreational marijuana.

“They have said they’re not going to enter the adult-use business,” said Hoffman, adding that GFA Credit Union and BayCoast Bank are the only two institutions currently providing services to recreational marijuana businesses.

“That’s certainly not going to be sufficient as this industry evolves,” said Hoffman.

Other small banks have quietly signaled they will support adult-use marijuana businesses, but a large bank like Century’s refusal highlights a glaring issue with federal regulations.

“Banking is a challenge, and I’ve been very public about that for a long time. Because of the federal prohibition, banks for the most part have been leery about entering into this business to support licensees,” said Hoffman.

The Senate passed legislation in 2014, called the Rohrabacher-Blumenauer Amendment, that bars the U.S. Department of Justice from using taxpayer dollars to prevent states from implementing medical marijuana laws.

That law doesn’t address recreational marijuana. Century CEO Barry Sloane told the Boston Business Journal Thursday that the law would need to be updated in order for them to service the adult-use industry in the Bay State.

Warren and Sen. Eric Gardner (R-Col.) filed legislation earlier this year meant to address some banking issues, stating that legal marijuana transactions under state law “shall not constitute trafficking,” under the Controlled Substances Act.

But Hoffman was unsure as to whether the legislation would address Sloane’s specific needs.

“It won’t fix everything and would still have some challenges for banking, but it will I think make things easier,” he said. “The thing that would make it very straightforward is taking it off schedule one.”