Nearly 500 long-term care pharmacies signed a letter urging Congress to prohibit certain Medicare reimbursement practices, the Senior Care Pharmacy Alliance announced Thursday.

Some large Medicare prescription drug plan sponsors (PDPs) have put in place a fee structure that reimburses LTC pharmacies based on the dispensing of drugs for a particular number of days. This could lead to higher costs and wasted medications, according to the pharmacies that signed the Oct. 24 letter. The practice also flies in the face of the Affordable Care Act’s short-cycle dispensing program, they argue. They say a better system would be to pay pharmacies a “flat, professional fee” for each prescription that is filled.

“Tying the professional fee to the amount of medication dispensed ignores the clinical oversight necessary to provide care under the unique CMS requirements for LTC pharmacies,” the letter states.

The letter was addressed to Sen. Ben Cardin (D-MD) and applauded the Medicare Efficient Drug Dispensing Act of 2013. Cardin and Sen. Barbara Mikulski (D-MD) introduced the bill last month. It would prohibit the reimbursement structure that the pharmacies oppose.

The bill has been referred to the Senate Committee on Finance, according to the Senior Care Pharmacy Alliance. The organization says it will work with committee members to advance the legislation.