Dialysis center operator DaVita Inc. said Tuesday it expects to receive a subpoena from federal investigators looking into payments made to the company for dialysis services in New York.

The company said it has been advised to expect a request for documents from the Office of Inspector General for the U.S. Department of Health and Human Services in connection with an earlier investigation by Justice Department officials in New York state. The probe involves payment for infusion drugs covered by the New York Medicaid payment system for dialysis.

DaVita has received subpoenas from U.S. Justice Department officials in Missouri and Colorado as well as Health and Human Services officials in Texas.

"We intend to cooperate with the government to provide responsive documents," DaVita said in a statement. "To the Company's knowledge, no proceedings have been initiated against it at this time, although the company cannot predict whether proceedings might be initiated."

The cost of dialysis services is a major concern for state and federal government officials because the vast majority of U.S. kidney disease patients receive care through the Medicare and Medicaid health systems. Medicare is the federally funded health program for seniors and the disabled. Medicaid is a jointly funded federal-state plan for low-income Americans.

Earlier this year Medicare began using a new bundled payment system to pay providers for dialysis services. The system essentially pays dialysis companies to treat patients more efficiently.

Shares of DaVita Inc. fell 80 cents, or 1.2 percent, to $68 in morning trading.