MADISON, Wis. (AP) — The Wisconsin Assembly is slated to vote Tuesday on a bipartisan bill designed to lower the cost of prescription drugs.

The measure is part of a growing call nationwide to do something about rising prescription drug prices. A lack of transparency has created a system in which drugmakers, middlemen called pharmacy benefit managers and other health care providers all benefit from increasing prices.

The bill up for a vote Tuesday targets pharmacy benefit managers, a critical part of the distribution and sales chain between manufacturer and consumer. They bargain drug prices on behalf of insurers and employers, manage plans, and process claims. But most of their work and terms of the agreements they reach are hidden to people buying prescriptions.

The goal of the proposal is to offer protections for consumers and small pharmacies. Some Democrats say the measure is not as strong as it could have been. Advocates, including groups representing consumers, say that while it’s not perfect, the bill is a step forward.

“It could be improved and it will be,” said Democratic Rep. Deb Kolste, of Janesville, ahead of Tuesday’s debate. “This bill is better than what we have now.”

The proposal requires pharmacy benefit managers to be regulated by the state insurance commissioner. Gag clauses in pharmacy benefit manager contracts would be prohibited, thereby allowing pharmacists to tell customers about cheaper options, including paying cash if that’s less than their insurance co-payment. There would also be fewer instances where pharmacy benefit managers could deny a claim.

Wisconsin would join 33 other states that have some form of regulation for the industry if the measure passes both the Assembly and Senate and is signed into law by Democratic Gov. Tony Evers.