UnitedHealthcare mentioned in the big anti-merger filings

The Justice Department's move to block two huge mergers is the story of the day when it comes to health insurance.

Anthem-Cigna? Aetna-Humana?

No and no, the government says.

The four companies round out the Big Five health insurers nationally, with Minnetonka-based UnitedHealthcare the biggest of the bunch right now.

A UnitedHealthcare spokesman said the company had no immediate comment on the government's lawsuits.

To be clear, UnitedHealthcare is not a defendant in either lawsuit. But the government makes reference to United a few times in making the case that the proposed mergers would hurt competition.

In the filing to block the $54 billion Anthem-Cigna deal, the Justice Department describes a "bidding frenzy" among the Big Five insurers during the spring and summer of 2015. At the time, UnitedHealthcare made bids for Aetna and Cigna, the government says.

The lawsuit states: "Notably, current market concentration levels understate the competitive harm likely to result from the proposed merger because both Humana and UnitedHealthcare — the fourth- and fifth-largest insurers in the Denver area — have announced that they will not offer individual health-insurance plans in Colorado in 2017, leaving Kaiser as Anthem and Cigna's only significant competitor."

The filing to block the proposed $37 billion Aetna-Humana deal also mentions UnitedHealthcare's pullback from the exchanges. Without mentioning United, the government also talks about the potential impact of an Aetna-Humana deal on the Medicare market, where the insurers sell what are called "Medicare Advantage" health plans.

A report last year from the Kaiser Family Foundation calculated Medicare Advantage market shares for UnitedHealthcare (20 percent), Humana (19 percent) and Aetna (7 percent), and concluded the merged company would overtake UnitedHealthcare as the market's biggest player.