A federal court in Massachusetts has allowed an antitrust lawsuit to move forward against five of the largest health insurers in the United States, rejecting multiple motions to dismiss in a case that could reshape how out-of-network medical claims are priced.
The ruling, issued by the US District Court for the District of Massachusetts, consolidates claims filed by healthcare providers in California, New Jersey and Kansas who treated policyholders of Aetna Inc., Cigna Group, Elevance Health Inc., Humana Inc. and UnitedHealth Group Inc.
The providers allege the health insurers used repricing technology from Zelis Healthcare LLC to systematically reduce out-of-network reimbursements.
Providers claim Zelis' tools forced them to accept "severely downwardly adjusted" reimbursements, enter one-sided negotiations, or file appeals that rarely result in increased payments.
Zelis is compensated based on the difference between what providers charge and the amount ultimately paid.
The court pointed to allegations that Zelis repriced a claim from Pacific Inpatient Medical Group Inc. at a discount of 88%, which the provider said was below market prices. That figure is not an outlier.
Court filings from law firm Hartley LLP, which filed the first Zelis case in March 2025, allege providers faced payment amounts as low as 1% of their invoiced charges.
Zelis, founded in 1995, serves more than 750 payers. Bain Capital and Parthenon Capital hold majority ownership. Bloomberg reported in September 2024 that the two firms were exploring a minority stake sale that could value Zelis at around $17 billion.
Zelis has previously denied the accusations, stating the complaints are mistaken about its clients, operations and the benefits it provides.
The health insurers argued providers could have negotiated higher rates or balance-billed patients directly. The plaintiffs responded that repriced claims were not open to negotiation and that balance billing is largely prohibited.
The No Surprises Act, which took effect in January 2022, bans balance billing for emergency services and certain non-emergency care at in-network facilities, reinforcing the providers' position.
The carriers also argued their use of Zelis lowered costs for policyholders. The Massachusetts court said lower prices do not justify price-fixing agreements.
The case mirrors a parallel and larger antitrust lawsuit against MultiPlan Inc., another repricing company, pending in the Northern District of Illinois. Providers in that case have accused MultiPlan and health plans of conspiring to underpay by roughly $19 billion per year. The US Department of Justice weighed in on the providers' side in March 2025.
Law firm ArentFox Schiff has noted these cases form part of a broader wave of algorithmic pricing litigation that is testing the boundaries of data-driven collaboration among competitors.
If courts ultimately find the repricing model constitutes price-fixing, the entire third-party repricing industry may need to restructure.
In allowing the antitrust lawsuit to proceed, the Massachusetts court found there is a legitimate dispute over whether Zelis' services amount to a price-fixing agreement among competitors or function as another pricing option for payers.
