The Biden administration's first major step toward imposing limits on the pharmacy benefit managers who act as the drug industry's price negotiators is backfiring, pharmacists say. Instead, it's adding to the woes of the independent drugstores it was partly designed to help.

The so-called PBMs have long clawed back a fee from pharmacies weeks or months after they dispense a drug. A new rule, which governs Medicare's drug program, is set to take effect Jan. 1 and requires PBMs to take most of their "performance fees" at the time prescriptions are filled.

The clawbacks have ballooned from about $9 million in 2010 to $12.6 billion in 2021, according to the Medicare Payment Advisory Commission, an agency created to advise Congress on the program for people who are 65 and older or have disabilities.