The U.S. Department of War has activated military versions of OpenAI's ChatGPT and xAI's Grok on its central generative-AI environment, GenAI.mil, expanding access to more than three million service members, civilians, and contractors for unclassified work. The rollout, announced on August 31, 2026, marks the operational stage of a collaboration formalized with OpenAI in 2025 and follows months of security testing and integration.
Both tools received accreditation to handle Controlled Unclassified Information at Impact Level 5, allowing use with sensitive but unclassified government material while keeping data isolated from commercial versions. Officials said data processed through ChatGPT Mil remains inside the government environment and is not used to train OpenAI's public or commercial models.
ChatGPT Mil is designed to feel familiar to users of the public product, with chat, file uploads, projects, and custom GPTs. The department said it is especially useful for document-intensive processes such as policy drafting, logistics coordination, contracting reviews, and report generation. The system is intended to automate routine writing, analysis, and synthesis so personnel can focus on higher-priority operational and decision-making work.
GenAI.mil launched in December 2025 with Google's Gemini as its first model and has enrolled more than 1.7 million users out of the department's workforce of more than three million. The addition of Grok and ChatGPT turns the portal into a multi-vendor marketplace, which the Pentagon framed as a way to avoid dependence on any single supplier. The Pentagon said the Grok release enables forces to 'execute missions faster and with greater precision,' citing deep-thinking inference, modes of reasoning called Auto, Fast, and Expert, and reusable 'playbooks' for institutional knowledge. Applications range from acquisition market research to supply chain work.
Anthropic's Claude remains excluded from GenAI.mil despite a federal court ruling. The dispute began after Defense Secretary Pete Hegseth in February 2026 called Anthropic a Supply-Chain Risk to National Security, following President Donald Trump's order for agencies to stop using the company's technology. Anthropic, which signed a $200 million Pentagon deal in July, wanted written assurances its models would not be used in fully autonomous weaponry or mass domestic surveillance. The Pentagon demanded unrestricted access for all legal purposes and set a February 27 deadline that was not met. Anthropic called the label 'unprecedented' and challenged it in court. U.S. District Judge Rita Lin expressed First Amendment concerns and on August 27, 2026, issued a 59-page ruling striking down the Pentagon's supply-chain risk designation. However, defense staff currently gain access to OpenAI and xAI tools, while Anthropic remains locked out of the portal pending the outcome of a D.C. Circuit Court appeal.
The expansion is overseen by the Chief Digital and AI Office and the Office of the Under Secretary of War for Research and Engineering. Department statements framed the launch as consistent with the White House AI Action Plan and its strategy of treating advanced models as a force multiplier for readiness and decision advantage. Current deployment is limited to unclassified work, with separate efforts under way for classified networks and combat-related applications.
