Dentists file class action lawsuits against Delta Dental in four states

Dentists have filed new class action lawsuits against Delta Dental organizations in four states, seeking class-wide relief under state law while a federal antitrust case continues on an individual basis.

The complaints, filed April 30 in California, Wisconsin, Michigan and Massachusetts state courts, allege that Delta Dental entities engaged in anticompetitive conduct that suppressed reimbursement rates paid to dentists and limited competition in dental insurance markets. 

The new filings follow developments in the federal case, which has been pending since 2019. Recently, in September 2025, the U.S. District Court for the Northern District of Illinois denied certification of a nationwide class. The plaintiffs sought to appeal that decision, but the U.S. Court of Appeals for the Seventh Circuit declined to permit immediate review. In January 2026, the trial court also denied a request to amend the complaint to add state-based class claims and instead moved forward with the case on the individual federal claims of the named plaintiffs.

State lawsuits filed

The four state complaints were brought by dental providers against the Delta Dental entity operating in that state. The complaints can be accessed here: California, Wisconsin, Michigan and Massachusetts.  Each lawsuit seeks to represent a class of dentists and dental practices within that state that participate in Delta Dental networks. 

According to the complaints, the cases pursue statewide class claims following the federal court’s decisions declining to certify a nationwide class and declining to incorporate state classes into the federal proceedings. The complaints state that the federal court did not address the merits of the state-based class claims.

Allegations mirror federal case

The state complaints are based on issues similar to those raised in the ongoing federal litigation. They allege that Delta Dental entities agreed not to compete with one another across geographic territories and instead operated within assigned service areas. The complaints also assert that Delta Dental organizations coordinated policies and practices that reduced reimbursement rates paid to dentists, including through the sharing of pricing-related information.  

Across all four states, the complaints assert that Delta Dental organizations hold substantial market share—generally described as exceeding 50%—and that this position allows them to influence reimbursement levels and conditions for participation in their networks.

Alleged impact on dentists 

The complaints state that participating dentists have limited ability to opt out of Delta Dental networks because of the size of Delta’s insured population in each state. As described in the filings, providers must either accept the reimbursement rates offered under Delta Dental participation agreements or risk losing access to a significant portion of their patient base.

Plaintiffs further allege that reimbursement rates have been reduced or maintained below market levels over time, even as insurance premiums increased. 

Proposed classes and claims

Each complaint seeks certification of statewide classes of dental providers, including dentists and dental practices that participated in Delta Dental networks during the relevant time period.

The lawsuits seek both injunctive relief and monetary damages, including treble damages where permitted by state law. The complaints also request additional remedies such as restitution and measures aimed at restoring competition.

Federal case continues