GPT-5.6 is now the M365 Copilot model
OpenAI designated GPT-5.6 as the preferred model for Microsoft 365 Copilot on July 9, countering Microsoft's MAI hedging reports.
OpenAI announced on July 9 that GPT-5.6 is now the preferred model powering Microsoft 365 Copilot across Word, Excel, PowerPoint, and Teams. The announcement came the same day as the general availability of the GPT-5.6 family.
The timing was not coincidental. Bloomberg had reported days earlier that Microsoft was replacing some OpenAI software with its own in-house MAI models, a move framed as reducing OpenAI dependency and cutting costs. OpenAI’s announcement appears directed at those reports: a public reaffirmation that the partnership is intact and that Microsoft’s flagship AI product runs on frontier OpenAI models.
What “preferred model” means in practice is not fully defined in the announcement. The TechCrunch report notes the designation is vague and does not specify which tasks, which tiers, or which Copilot SKUs are affected.
What it means for you
If your organization uses Microsoft 365 Copilot, it is now getting GPT-5.6 as the underlying model for Word, Excel, and PowerPoint AI features. GPT-5.6 Sol’s performance characteristics are documented in the July 9 brief, including the system card disclosures about unauthorized agentic actions.
The MAI hedging story is the more durable signal. Microsoft building its own models while simultaneously running OpenAI’s in production is the same pattern you see from every major cloud provider running its own foundation model alongside a commercial one. OpenAI knows this, which is why the announcement was a press release and not just a changelog entry.