Appeals Court Upholds Pentagon Ban on Anthropic AI Models

TLDR

• A federal appeals court in Washington, D.C. upheld the Pentagon’s decision to blacklist Anthropic.
• The Department of Defense labeled Anthropic a supply chain risk in March 2026.
• The ruling keeps Claude models banned from Pentagon systems and blocks defense contractors from using them.
• The 2-1 decision rejected Anthropic’s claim that the ban was unconstitutional and arbitrary.
• Anthropic says it is considering further legal options, including a Supreme Court appeal.

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A federal appeals court in Washington, D.C. has upheld the Pentagon’s blacklisting of Anthropic. The ruling came down on Friday from the U.S. Court of Appeals for the District of Columbia Circuit.

🚨BREAKING: Claude is officially a NATIONAL SECURITY THREAT and is BLACKLISTED from the ENTIRE defense supply chain

>anthropic: no autonomous weapons, no mass surveillance, no exceptions
>pentagon blacklists claude as an active national security threat
>anthropic sues

Federal… pic.twitter.com/eLS8G1cRIj

— NIK (@ns123abc) September 25, 2026

The panel voted 2-1 against Anthropic. Judges Gregory Katsas and Neomi Rao formed the majority. Judge Karen LeCraft Henderson dissented.

The case centers on a decision made in March. The Department of Defense labeled Anthropic a “supply chain risk.” That label is usually reserved for companies tied to foreign adversaries.

The designation means the U.S. military cannot use Anthropic’s Claude models. It also stops defense contractors from using Claude in their work with the Pentagon.

How the Dispute Started

Anthropic had been working with several U.S. agencies, including the Pentagon. In July 2025, the company signed a $200 million contract with the Department of Defense.

Talks broke down that September. The Pentagon wanted full access to Claude for “all lawful purposes.” Anthropic wanted limits in place, including rules against autonomous weapons and domestic surveillance.

The two sides could not agree. Defense Secretary Pete Hegseth accused Anthropic of trying to hold veto power over military decisions.

Judge Katsas wrote that Hegseth raised concerns about AI models shutting down unexpectedly. He also cited worries that Claude could be manipulated. Anthropic has denied these claims.

Katsas said the final call on these tradeoffs belongs to the president and the defense secretary, not the courts.

What Happens Next for Anthropic

Anthropic sued the government in two separate courts earlier this year. One case was filed in San Francisco. The other was filed in the D.C. Circuit.

A judge in San Francisco ruled last month that one part of the Pentagon’s designation was illegal. That ruling is separate from Friday’s decision and has not been appealed by the government.

Friday’s ruling upheld the second designation used by the Pentagon. Because the two designations rely on different legal grounds, the D.C. court’s ruling did not cancel out the California ruling.

This means Anthropic can still work with some government agencies and contractors under the California decision. But the Pentagon ban remains in place.

Anthropic released a statement after the ruling. A spokesperson said the company disagrees with the decision.

“Another federal court has already held the government’s parallel designation unlawful,” the spokesperson said. “We remain confident in our position and are considering all options, including further review.”

The appeals panel gave Anthropic time before the ruling takes full effect. The company can ask for a rehearing by the same panel. It can also request a rehearing by the full D.C. Circuit, known as an en banc hearing.

Anthropic could also take the case to the Supreme Court.

The relationship between Anthropic and the Trump administration has been tense for months. President Trump has criticized Anthropic CEO Dario Amodei on social media several times.

Pentagon Undersecretary Emil Michael celebrated the ruling on social media Friday. He wrote that the decision means no private company will interfere with military decision-making.

Anthropic has not said which legal option it will pursue next.