The lawsuit, announced Tuesday, claims that the companies' noncompete clauses illegally prevent physicians and other health care providers from working for competing dialysis centers, effectively stifling competition and reducing treatment options for the roughly 9,000 Washington residents who rely on dialysis.

"These noncompete agreements are not just unfair to workers—they're bad for patients," Ferguson said in a statement. "By restricting the ability of health care providers to work for competitors, DaVita and Fresenius have limited the choices available to some of our most vulnerable residents. This lawsuit seeks to end these practices and restore competition in the dialysis market."

The complaint alleges that the noncompete agreements violate Washington's antitrust laws and a 2019 state law that restricts the use of noncompete clauses for employees earning less than $100,000 annually. The attorney general's office argues that the agreements have the effect of locking in patients by preventing new or expanding dialysis providers from hiring the staff they need to operate.

DaVita and Fresenius together control the vast majority of dialysis centers in Washington. According to the lawsuit, the companies' practices have made it difficult for independent dialysis providers to enter the market or expand, ultimately reducing the number of treatment options available to patients.

Kidney dialysis is a life-sustaining treatment for people with end-stage renal disease, requiring patients to undergo sessions several times a week. Access to convenient, high-quality care is critical, and limited options can force patients to travel long distances or go without necessary treatment.

In a statement, DaVita said it believes its agreements are lawful and that it will defend against the lawsuit. "We are committed to providing high-quality care to our patients and believe our employment practices are fair and legal," the company said. Fresenius did not immediately respond to a request for comment.

The lawsuit is the latest in a series of actions by Washington officials to crack down on noncompete agreements, which have been criticized for suppressing wages and limiting worker mobility. In recent years, the state has taken steps to ban or restrict such agreements, and this case could set a precedent for how they are applied in the health care sector.

Patient advocates praised the lawsuit. "This is a win for patients and for health care workers," said a spokesperson for the Washington State Hospital Association. "Noncompete agreements have no place in health care, where the priority should always be patient access and quality of care."

The lawsuit seeks injunctive relief to stop the companies from enforcing the noncompete agreements, as well as civil penalties and other remedies. A court date has not yet been set.

For the thousands of Washingtonians who depend on dialysis, the outcome of this case could have a direct impact on the availability and accessibility of their care. As the state argues, breaking down barriers to competition may be essential to ensuring that all patients have access to the treatment they need.