LANSING, MI — Michigan Attorney General Dana Nessel has filed a federal lawsuit accusing Blue Cross Blue Shield of Michigan of illegally operating a health insurance monopoly in the state.
The case was filed Thursday in U.S. District Court for the Eastern District of Michigan. Nessel’s office is seeking civil penalties, restitution and other financial relief, along with findings that the company violated the Sherman Act and the Michigan Antitrust Reform Act.
According to the attorney general, the company’s market position has pushed up costs for both employers and consumers. The complaint says the insurer’s conduct has also hurt competition in the broader health care market.
State says Blue Cross controls a dominant share of Michigan insurance markets
Nessel said Blue Cross Blue Shield of Michigan controls 65% of the state’s health insurance market and 79% of PPO insurance plans. Her office says that level of dominance was not the result of ordinary competition.
The lawsuit alleges the company gained and protected its position through a series of illegal agreements within the Blue Cross Blue Shield network. Those agreements, the attorney general said, were used to divide customers and territories, limit product choices and reduce competition for health insurance services.
That claim goes to the heart of the case: whether the insurer’s size reflects market success or unlawful coordination. The state says the answer is the latter.
Attorney general links the lawsuit to rising premiums and care delays
The lawsuit argues that Michigan residents and employers are paying the price through higher premiums and more expensive care. Nessel said the insurer’s alleged conduct has raised health care costs across the state.
Her office cited several figures to support that argument. More than 40% of Michigan small-business owners say rising health care costs are a financial burden, according to information the office provided. More than 68% of Michigan adults surveyed in 2025 said they had at least one instance of skipping or delaying medical care because of possible costs.
The attorney general’s office also said Michigan ranks 20th nationally for the number of people with medical debt in collections.
Hospitals and medical providers face pressure, state says
Nessel’s office says the insurer’s market power has not only affected customers, but also medical professionals and providers. The complaint says some providers have been forced to cut services, move staff into administrative roles, or leave Michigan altogether.
As one example, the office pointed to the closure of Sturgis Hospital in St. Joseph County near the Michigan-Indiana border. The hospital closed in June, citing inadequate reimbursement for rural health care services.
The lawsuit uses that closure to illustrate what the state sees as the broader impact of reimbursement pressure. In the attorney general’s view, weakened competition can ripple through hospitals, clinics and local care options.
Premium increases and network disputes add to the stakes
The complaint also points to recent premium increases as evidence that consumers are feeling the strain. For 2026, premiums rose 23% to 24% for individual plan members and 11.2% for small group markets, according to the lawsuit.
Another issue highlighted in the filing is an earlier contract dispute between Michigan Medicine and Blue Cross Blue Shield of Michigan. A tentative agreement was reached in late May, just weeks before the previous contract was set to expire.
That agreement mattered because it affected whether care would be considered in network, which can make a major difference in what patients pay out of pocket. The state says those kinds of disputes show how much leverage the insurer holds.
Blue Cross says competition exists across Michigan insurance markets
Blue Cross Blue Shield of Michigan pushed back strongly in a statement. The company said it was “blindsided” by the announcement and has not yet been served, so it cannot comment on the merits of the case.
The insurer said it “fundamentally” disagrees with Nessel’s description of the market as uncompetitive. In its view, competition is active throughout Michigan, with strong local and national insurers competing every day.
The company also said it has provided coverage in every county for nearly 90 years. The response sets up a high-stakes legal fight over how the state’s insurance market actually works and whether one company has crossed the line into unlawful dominance.
