The U.S. government will select the 10 costliest prescription medicines to Medicare for negotiating prices with drugmakers starting early next year, the program’s top official said on Friday.

The U.S. health department proposed on Tuesday three new pilot projects aimed at lowering prescription drug prices for people enrolled in government health insurance plans, including offering some essential generic drugs for $2 a month.

The U.S. government will begin imposing penalties in 2025 on drug companies that charge its Medicare program prices that rise faster than inflation, the Centers for Medicare & Medicaid Services said on Thursday.

As early as 2023, pharmaceutical manufacturers and payers will have to contend with one of the more imminent potential impacts of the law: inflationary rebates for Medicare utilization.