The Justice Department on Monday filed a notice of appeal to the U.S. Court of Appeals for the Ninth Circuit, challenging a federal judge’s August ruling that blocked the government’s ban on agency use of Anthropic technology, according to the filing in the U.S. District Court for the Northern District of California.
The two-page notice, filed in Anthropic PBC v. U.S. Department of War, appeals Judge Rita F. Lin’s Order on Cross-Motions for Summary Judgment, Order of Final Relief and Final Judgment, all entered Aug. 27, 2026. Bloomberg Law reported the filing earlier Monday.
What the August ruling did
The case challenges actions taken in February and March, when, according to Lin’s opinion, President Trump and Secretary of War Pete Hegseth designated Anthropic a supply chain risk to national security, ordered federal agencies to stop using its products and barred defense contractors from doing business with the company.
Lin’s order declared that those actions violated the First Amendment “because they are unlawful retaliation against Anthropic for constitutionally protected expressive activities,” and violated the Due Process Clause. It vacated the supply chain designation and permanently enjoined most defendants from implementing the challenged actions. The government won on one count, a separation of powers claim, and on all claims against several agencies that the order calls non-participating.
In her opinion, Lin wrote that the government’s “contemporaneous words and deeds confirm that the challenged actions were based on a desire to make a public example out of Anthropic for its ‘arrogance’ in criticizing the government.”
A parallel case
A separate case over a second designation, under a different statute, is before the D.C. Circuit. A panel there ruled against Anthropic 2-1 on Sept. 25, and Anthropic has asked the full court to rehear it, according to the company’s S-1 filing.
That prospectus, made public Monday, says government agency contracts were about 1% of revenue in each period presented. It also says Anthropic “cannot be certain that the resolution of these lawsuits will not adversely affect our ability to sell to government agencies and other customers that sell products and services to the U.S. government.” AI Tech Daily covered the S-1 filing.
Earlier coverage: Pentagon says it has stopped using Anthropic products.
Sources
- Notice of Appeal, Anthropic PBC v. U.S. Department of War, No. 3:26-cv-01996-RFL, ECF 253 (N.D. Cal., October 26, 2026)
- Order of Final Relief, ECF 251 (August 27, 2026)
- Order on Cross Motions for Summary Judgment, ECF 250 (August 27, 2026)
- Bloomberg Law (Madlin Mekelburg): DOJ Appeals Court Ruling Lifting Ban on Agency Anthropic Use (October 26, 2026)
- Anthropic, PBC Form S-1 (October 26, 2026)