The latest attempt to curb drug prices would penalize pharmaceutical companies for raising prices faster than the rate of inflation.

Drugmakers will have to disclose a drug's cost if its price before rebates and discounts is above $35 for a month's supply.

A proposal to end drug rebates in Medicare would increase spending by about $170 billion over 10 years, CBO says.

The report is likely to give both opponents and supporters of Medicare for All ammunition.

The actions have raised questions about why it took public pressure before the companies altered their programs.

The scrutiny is part of a wider inquiry by lawmakers into U.S. drug costs that has involved several Senate hearings.

Lawmakers want to know how companies market the plans, what percentage of applicants are denied coverage, and what brokers are paid.

The measure, released by HHS on Thursday, would roll back so-called safe-harbor protections for drug rebates.