Justice Department Moves to Block Two Health Insurance Mega-Mergers by Reuters @FortuneMagazine July 21, 2016, 12:29 PM EDT E-mail Tweet Facebook Linkedin Share icons The U.S. Justice Department on Thursday sued to challenge two separate health insurance mergers, Anthem’s anthem purchase of Cigna ci and Aetna’s aet acquisition of Humana hum . In the suit against Anthem-Cigna, the antitrust regulators said the $45 billion combination would substantially lessen competition in an already consolidated industry, harming millions of Americans, doctors and hospitals. Cigna said it was currently evaluating its options. It does not believe the transaction would close in 2016, and the earliest it would close would be in 2017, “if at all.” Aetna and Humana said they plan “to vigorously defend the companies’ pending merger,” which is worth $33 billion. The Justice Department will hold an 11 a.m. news conference to announce significant antitrust news. There are currently five national health insurers, and the deals would reduce that number to three. The health insurers have argued that the deals would help them lower prices for consumers by expanding their reach at a time when the nation is facing a constant price rise. Antitrust regulators had been expected to file lawsuits aimed at blocking both deals by the end of next week, Reuters reported earlier this week. Shares of Humana fell 0.5% in mid-morning trading. Cigna, Aetna and Anthem shares were all up slightly.