Washington is about to move to stop two large health-insurer mergers, according to a report.

The Department of Justice is expected to file lawsuits to block Anthem’s $48 billion acquisition of rival health insurer Cigna and Aetna’s $37 billion deal to buy Humana, according to Bloomberg, which cited a person familiar with the matter.

Shares of Cigna are down 2.3 percent while Humana shares are off 5.2 percent. Anthem is seeing its shares fall 3.1 percent and Aetna’s shares are dipping 4.1 percent.

The transformative deals would mean the health insurance industry would have three large rivals instead of five.

Earlier this month, President Obama, writing in the Journal of the American Medical Association, hinted at such a move when he said he’s like to see more — not less — competition.

The final decision by the Justice Department could come this week and will be made by the end of the month, one of the people said.