Pentagon Adds ChatGPT and Grok to GenAI.mil

The Pentagon has switched on OpenAI's ChatGPT Mil and xAI's Grok for Government inside GenAI.mil, its internal AI platform. Google Gemini had been the only option there since the December 2025 launch. Defense Department staff can now pick between three rival models behind a single sign-in.

Two models, two pitches

The department frames the two arrivals differently. ChatGPT Mil is aimed at administration, logistics and planning — the desk work that fills the day in an organization of three million people. For Grok, the language turns notably more martial, with procurement analysis and supply chain management cited as use cases.

How either model differs technically from its civilian sibling is not spelled out in the available reporting. Nor are contract values, terms, or a timeline for full rollout disclosed.

1.7 million users — but not per model

The department puts the platform at more than 1.7 million users, measured against a base of over three million employees and military personnel. That figure covers GenAI.mil as a whole rather than any single model. How many of those people will open ChatGPT Mil or Grok instead of Gemini is not yet known.

Walled off from the commercial products

Both tools run in a dedicated secured environment, separated from the publicly available versions, according to the department. The stated purpose is to keep sensitive government data out of the vendors' commercial systems, and no user data is collected. These are the department's own assurances; no independent audit of them has been published.

The conspicuous gap: Anthropic

Anthropic's Claude remains off the platform. The Trump administration had labeled the company a supply chain risk, a designation a court declared unlawful in late August. The German-language edition of the report adds a second reason — that Anthropic declined to grant the Pentagon unrestricted use — but that detail does not appear in the same outlet's English version, so it rests on thinner evidence.

Whether the ruling clears a path for Claude to be added later is not addressed by either report. Both are built on two departmental press releases that could not be checked independently for this article.

Why it matters

A single-vendor deployment has become a multi-vendor one: three labs that compete for the same commercial customers now sit behind one government login. For readers in Europe, the arrangement itself is the interesting part — walled-off government editions as the price of admission to public-sector work.