On April 8, 2026, a federal appeals court in Washington, D.C. denied Anthropic's request to temporarily block the Department of Defense’s (DOD) blacklisting of the artificial intelligence company, as a lawsuit challenging the sanction continues to unfold [1]. The DOD had declared Anthropic a supply chain risk in early March, citing purported threats to U.S. national security from the company's technology. This designation requires defense contractors to certify that they do not use Anthropic's Claude AI models in their military-related work [1].
The appeals court stated, "the equitable balance here cuts in favor of the government," emphasizing the importance of judicial management over vital AI technology during an active military conflict versus the relatively contained financial harm to Anthropic [1]. As a result, Anthropic remains excluded from DOD contracts, and defense contractors are prohibited from using Claude for agency work, though they may use it in other contexts. However, Anthropic can continue working with other government agencies while litigation proceeds [1].
Previously, a San Francisco federal court granted Anthropic a preliminary injunction barring the Trump administration from enforcing a ban on the use of its Claude model, creating a split in judicial decisions [1]. The appeals court acknowledged that Anthropic "will likely suffer some degree of irreparable harm absent a stay," but characterized the harm as primarily financial. The court also noted that Anthropic had not demonstrated that its free speech had been chilled during the litigation [1].
Anthropic expressed gratitude that the court recognized the need for expedited resolution and voiced confidence that the courts would ultimately find the supply chain designations unlawful. The company reiterated its commitment to working productively with the government to ensure safe, reliable AI for all Americans [1]. Todd Blanche, the acting U.S. attorney general, described the decision as a "resounding victory for military readiness" [1].
CONCLUSION
The federal appeals court's decision to uphold the Pentagon's blacklisting of Anthropic marks a significant setback for the AI company, restricting its access to DOD contracts while litigation continues. Despite the financial harm acknowledged by the court, Anthropic remains optimistic about a favorable legal outcome and continues to engage with other government agencies. The ruling is seen as a strong affirmation of military priorities and supply chain security.