During the launch of GPT 5.6 on July 9, 2026, OpenAI announced that this new model will serve as the "preferred model" for Microsoft 365 Copilot. The software will be integrated across Microsoft's productivity suite, including PowerPoint, Word, Excel, and Cowork.

This announcement follows a Bloomberg report indicating that Microsoft has been integrating its own in-house MAI models into Office applications to reduce operational expenses. While the term "preferred model" remains loosely defined, OpenAI's statement aims to dispel rumors of a rift between the two companies.

Despite the move toward diversifying its AI stack with internal models, the partnership continues. OpenAI emphasized that the collaboration remains focused on expanding the reach of advanced AI to a broader range of organizations and individuals.