GPT-5.6 Named Microsoft 365 Copilot's Preferred Model

On July 9, 2026, OpenAI declared GPT-5.6 the "preferred model" for Microsoft 365 Copilot — the phrase appeared in the company's launch-day blog post for the model, clearly meant to reaffirm a partnership that has looked increasingly ambiguous lately, TechCrunch reports. GPT-5.6 will power Word, Excel, PowerPoint and Cowork.

The announcement came days after Bloomberg reported that Microsoft had begun swapping in its own in-house MAI models in place of some OpenAI-powered features — including in Word and Excel — as part of a cost-cutting push. TechCrunch itself notes that OpenAI's new statement "doesn't refute the previous reports" about Microsoft's shift toward its own models, and the company never spelled out what "preferred model" status actually means in practice.

OpenAI's only official quote, from its blog, stays vague: "Our partnership with Microsoft has always been about bringing frontier AI to more people." According to TechBuzz, the two companies' partnership is valued at $13 billion, and Microsoft's own AI business is on track to generate $10 billion in annual revenue by the end of the year, by the company's own projections, the outlet notes.

The upshot: the two versions of events aren't actually contradictory — GPT-5.6 remains Copilot's core engine, while Microsoft simultaneously builds out its own models so it can route specific workloads to whichever option is cheaper or faster, rather than relying on a single supplier. The public "preferred model" label reads more like marketing framing than a technical commitment.

This article is for informational purposes only and does not constitute investment advice.