The pressure on pharmacy benefit managers mounts on Capitol Hill as the leaders of the Senate health committee unveiled the latest bills targeting prescription drug costs on Tuesday.

Senate Health, Education, Labor and Pensions Committee Chair Bernie Sanders (I-Vt.) and ranking member Dr. Bill Cassidy (R-La.) introduced a package of measures and plan to hold a hearing on PBMs and pharmaceutical prices next Tuesday, they announced in a joint news release. Sens. Patty Murray (D- Wash.) and Dr. Robert Marshall (R- Kan.) cosponsored the bills.

Sanders and Cassidy’s Pharmacy Benefit Manager Reform Act of 2023 would ban spread pricing, require PBMs to pass through the full value of drugmaker rebates to customers, disclose drug prices and dispensing fees, and report how much money PBMs receive from pharmaceutical company copayment assistance programs.

“We are happy to announce that we’ve come to an agreement to consider critical pieces of legislation to reform pharmacy benefit managers and expand the availability of low-cost generic drugs through the HELP Committee,” Sanders and Cassidy said in the news release.

The health insurance trade group AHIP and PBM trade group the Pharmaceutical Care Management Association did not immediately respond to interview requests.

Pharmacy benefit managers face increasing scrutiny from legislators, regulators and law enforcement agencies at both the federal and state levels, and several bills focused on the issue have debuted in Congress this year already. Democrats and Republicans have seized on rising drug prices and the PBM industry’s opaque business practices to criticize companies such as CVS Caremark, Express Scripts and OptumRx. A number of states have sued PBMs, alleging they withheld money due Medicaid programs, and the Federal Trade Commission has been investigating the sector since last year.

Senate Finance Committee Chair Ron Wyden (D-Ore.) and ranking member Mike Crapo (R-Idaho) introduced a PBM bill of their own last week following a hearing in March. House Oversight and Accountability Committee Chair James Comer (R-Ky.) launched an investigation into PBMs last month.

In addition to the PBM bill, the Senate HELP Committee leaders introduced other drug pricing legislation Tuesday that aim to speed generic medicines to market and promote the availability of so-called orphan drugs, which are medicines for ailments so rare that drugmakers cannot profit from selling them.

PBMs appear to be feeling the heat and taking steps to evade new regulations by voluntarily adopting new policies. Cigna subsidiary Express Scripts created an optional pass-through pricing program for employers, increased payment disclosures to federal regulators and committed to paying higher fees to rural pharmacies. UnitedHealth Group’s OptumRx also recently offered a pass-through payment model for employers and announced new consumer pricing tools.