At issue is how the government reimburses dialysis clinics. Until 2011, the government paid clinics for each dosage of an anti-anemia drug administered, a practice that led to concern that clinics were overusing the drug. But after adopting a flat fee for dialysis, the use of the drug plunged, while the dialysis companies’ earnings margins rose. That prompted Congress to order a cut in the drug fee.

Some outside experts say the industry is now effectively enlisting patients and members of Congress as a lobbying tool to protect their payments. The real problem, they say, is that the industry continues to open or acquire new clinics even as growth in the number of patients on dialysis nationwide has slowed.

“Patients should not be used as pawns in a series of scare tactics to protest a change in a payment,” said Richard Berkowitz of Skokie, Ill., who said he was repeatedly pressured when he recently visited his dialysis clinic to sign a petition protesting the cuts, even though he routinely does dialysis on his own at home.

The industry — which lists dozens of lobbyists, including former Representative Earl Pomeroy, Democrat of North Dakota, and Thomas A. Scully, who ran the Medicare program from 2001 to 2004 — has proved its clout in Washington before. It persuaded Congress to pass legislation that as of 2011 allowed the industry to receive an annual adjustment in its reimbursement rate, which it will get in the coming year. That will slightly reduce the impact of the other proposed cut.

The federal government for decades has covered the cost of what is called end-stage kidney disease, the only chronic disease that has this automatic coverage. The benefit has cost the government more than $32.9 billion a year, the biggest part of it for dialysis. The result is that about 90 percent of the dialysis patients served by a company like DaVita rely at least in part on federal insurance.