Key committees in both houses of Congress on Wednesday voted to advance legislation targeting the actions of pharmacy benefit managers.

The Senate Finance Committee, which has jurisdiction over Medicare and Medicaid, overwhelmingly passed the Medicare PBM Accountability Act. The bill would establish new requirements for PBMs to submit annual reports to Medicare drug plans, disclosing price negotiations and rebate information that affect what seniors pay in premiums and co-pays. With six PBMs now controlling 95% of the private market, enhanced transparency around how PBMs are delivering and paying for prescription drugs would help Medicare drug plans select PBMs that best serve the needs of beneficiaries, lowering costs for seniors and taxpayers, said Catherine Cortez Masto, D-Nev., who sponsored the bill.

"I will continue working to stop these companies from squeezing our families by passing this commonsense bill and getting seniors on Medicare the best possible deal on their prescription drugs," she said.