DaVita's stock was off 7.8% at $51.17.
On Wednesday the U.S. Department of Health and Human Services is expected to disclose plans to beef up efforts to prevent kidney disease and shift more treatment to homes and away from dialysis centers.
The new policy is also expected to encourage more kidney transplants, which could reduce the number of patients served by DaVita's dialysis centers.
The policy plan, reported by Politico, has the potential to shake up the $24 billion dialysis industry. DaVita is a leading player there, along with Fresenius Medical Care AG (FMS) - Get Report . Fresenius shares were 5.6% lower Tuesday at $37.22.
It also comes as DaVita prepares to double down on its dialysis-center business, following its $4.3 billion deal to sell DaVita Medical Group, a unit separate from its dialysis business.
Medicare, the federal health insurance program for the elderly, spends more than $114 billion a year on kidney care, with the majority of it going toward patients with chronic kidney disease.
DaVita and Fresenius "effectively control the market and neither currently are financially incentivized to change behavior," Chris Meekins, a Raymond James analyst and former HHS official, told Politico.
"The administration needs to put forward enough carrots to encourage new market entrants and enough sticks to force the current players to alter behavior if real change is to occur."