A federal judge has blocked the proposed $54 billion merger of two major health insurance companies, Anthem and Cigna, after the Justice Department concluded that the deal would reduce competition in the health insurance market and raise prices.

Judge Amy Berman Jackson of the U.S. District Court for the District of Columbia made the ruling.

Anthem is determined to ensure Wednesday’s decision isn’t the final word on the issue. The company said in a statement Thursday that it “promptly intends to file a notice of appeal and request an expedited hearing.”

The Justice Department announced last summer that it would oppose both the Anthem-Cigna merger and one by Aetna and Humana, These are four of the major five insurers in the nation.

Both mergers have now been blocked in separate federal court cases citing adverse effects on competition and pricing.

Then-Attorney General Loretta Lynch said: “If allowed to proceed, these mergers would fundamentally reshape the health insurance industry. They would leave much of the multi-trillion dollar health insurance industry in the hands of three mammoth insurance companies, drastically constricting competition in a number of key markets that tens of millions of Americans rely on to receive health care. … If these mergers were to take place, the competition among these insurers that has pushed them to provide lower premiums, higher quality care and better benefits would be eliminated.”

The California Insurance Commissioner said “Today’s federal court decision to block the merger of two of the nation’s largest health insurers is a significant win for consumers who need more choice, not less, in an already highly concentrated health insurance market. Bigger was definitely not better when it comes to the Anthem-Cigna merger.”

“Last year I held an extensive public hearing on the proposed merger. After reviewing all the evidence, I concluded the Anthem-Cigna merger was bad for consumers and businesses, and bad for health insurance and health care markets. I issued detailed findings of fact and law and urged the U.S. Department of Justice to sue to block this merger because it is anti-competitive and would harm California consumers, businesses, and the California health insurance market.”

The commissioner concluded that “Allowing a merger between two of the largest health insurers in the country would have increased the price of health insurance, and decreased choice and the quality of healthcare for consumers and businesses. I am very pleased the federal district court entered a decision consistent with my findings and legal conclusions that the Anthem-Cigna merger is anti-competitive.”