The Department of Justice (DOJ) has joined with the attorneys general of Minnesota and New York in filing a civil lawsuit to block the acquisition of Change Healthcare by UnitedHealth Group. The lawsuit claims that the acquisition would hurt competition in the commercial health care market and impede the development of technology to process health insurance claims and reduce insurance costs.

In a statement, U.S. Attorney General Merrick B. Garland said: “Quality health insurance should be accessible to all Americans. If America’s largest health insurer is permitted to acquire a major rival for critical health care claims technologies, it will undermine competition for health insurance and stifle innovation in the employer health insurance markets. The Justice Department is committed to challenging anticompetitive mergers, particularly those at the intersection of health care and data.”

The lawsuit asserts that through the purchase of Change Healthcare, priced at $13 billion, UnitedHealth Group would gain access to sensitive data from rival insurance companies, which United could then use to gain an unfair advantage in the health insurance market. Through the acquisition, Change Healthcare would cease to exist.

“The proposed transaction also would eliminate United’s only major rival for first-pass claims editing technology — a critical product used to efficiently process health insurance claims and save health insurers billions of dollars each year — and give United a monopoly share in the market,” according to a press release issued by the DOJ.

“Unless the deal is blocked, United stands to see and potentially use its health insurance rivals’ competitively sensitive information for its own business purposes and control these competitors’ access to innovations in vital health care technology,” said Doha Mekki, principal deputy assistant attorney general of the Justice Department Antitrust Division. “The department’s lawsuit makes clear that we will not hesitate to challenge transactions that harm competition by placing so much control of data and innovation in the hands of a single firm.”