OpenAI: GPT-5.6 is 'preferred model' for Microsoft 365 Copilot
Original: OpenAI says GPT 5.6 is the ‘preferred model’ for Microsoft Copilot 365 amid breakup chatter
Why This Matters
The OpenAI-Microsoft partnership underpins a major slice of enterprise AI adoption globally.
OpenAI announced on July 9, 2026 that GPT-5.6 will serve as the 'preferred model' powering Microsoft 365 Copilot, including Word, Excel, PowerPoint, and Cowork, amid reports that Microsoft was expanding use of its own in-house MAI models to cut costs.
During the launch of GPT-5.6 on Thursday, July 9, 2026, OpenAI designated the new model as the 'preferred model' for Microsoft 365 Copilot. The announcement came shortly after Bloomberg reported that Microsoft was replacing some OpenAI software with its own in-house models, known as MAI, to reduce expenses — specifically in productivity apps like Word and Excel. OpenAI addressed the speculation in a blog post: 'Our partnership with Microsoft has always been about bringing the benefits of advanced AI to more individuals and organizations, and we're excited to continue building on that shared commitment.' GPT-5.6 will support users across Microsoft's productivity suite, including Word, Excel, PowerPoint, and Cowork. However, the exact meaning of 'preferred model' remains undefined. Notably, prior reporting never claimed OpenAI would be fully removed from Microsoft's apps — only that Microsoft was increasingly supplementing with its own models. The new designation does not appear to contradict that earlier reporting.