OpenAI GPT-5.6 Is Now the Default Model in Microsoft 365 Copilot

OpenAI rolled out GPT-5.6 on July 9, 2026, designating it the new preferred model inside Microsoft 365 Copilot. The update covers five applications — Word, Excel, PowerPoint, Copilot Chat, and Cowork — and is framed around efficiency as much as raw capability. OpenAI describes GPT-5.6 as delivering “more useful work from every token, with stronger performance per dollar and on demand capability for the most complex tasks.”

In practical terms, the upgrade is designed to reduce the back-and-forth that typically makes AI-assisted work feel tedious. In Word, that means fewer rounds of prompting to arrive at a usable draft. In Excel, the model is built to move users from raw data to meaningful analysis with less friction. In PowerPoint, it’s supposed to turn rough ideas into polished slides with less manual intervention. And in Cowork, Microsoft’s cross-functional collaboration tool, GPT-5.6 is positioned to handle complex, multi-step tasks more autonomously.

“Microsoft 365 is where millions of people write, analyze, create, and collaborate every day,” Nikunj Handa, head of OpenAI’s API Product, said in a company announcement. “By bringing GPT‑5.6 to Microsoft 365 Copilot through the OpenAI API, we’re helping organizations get more useful work from every token, and more value from AI in the tools they already use.”

GPT-5.6 is not a single model but a family of three tiers: Sol, Terra and Luna, ranging from complex-task-optimized down to lightweight use cases. API pricing for developers reflects that range — Sol costs $5 per million input tokens and $30 per million output tokens, Terra is $2.50/$15, and Luna is $1/$6. Inside Microsoft 365 Copilot, however, Microsoft maps these tiers to vague interface labels like “Quick Response” and “Think Deeper,” leaving users largely in the dark about which variant is actually handling their request.

The Partnership Question Nobody Is Answering

The timing of this announcement carries some strategic weight. Just days before OpenAI’s announcement, Bloomberg reported that Microsoft had been quietly substituting some OpenAI models in Word and Excel with its own in-house MAI models, reportedly to cut costs. The “preferred model” framing reads, at least in part, as a public reaffirmation that the OpenAI partnership remains central — but neither company clarified what “preferred” means operationally, how work will be divided between GPT-5.6 and MAI models, or whether every tenant, region and feature received GPT-5.6 simultaneously on launch day.

“We can’t wait for customers to see what GPT‑5.6 in Microsoft 365 will do, enabling them to work even more effectively with AI in the tools they use every day,” said Nitin Agrawal, president of Copilot & Agents Core at Microsoft. 

The competitive backdrop matters here too. Microsoft’s main rival in AI-enhanced productivity software is Google, which has taken a notably different approach: Gemini AI is bundled into all Google Workspace tiers — Business Starter runs about $7 per user per month, Standard about $14 — with no separate AI add-on fee. Microsoft 365 Copilot, by contrast, remains a paid add-on: $18 per user per month for small businesses on a current promotional rate, or $30 per user per month for the full enterprise tier. Microsoft currently has about 20 million paid Copilot seats, up from 15 million at the start of 2026, but the pricing gap with Google remains a real friction point. A third entrant worth watching is Apple, which launched Apple Business in March 2026, integrating Apple Intelligence on-device across macOS and iOS — a pitch aimed squarely at regulated industries wary of sending sensitive data to cloud-based AI.

What This Means If You’re a Student

For students already inside the Microsoft 365 ecosystem, the GPT-5.6 upgrade is relevant and potentially free, depending on how your school is set up. Verified U.S. college students can access 12 months of Microsoft 365 Premium at no cost — which includes Copilot built into the full desktop suite — and Copilot Chat is available at no additional charge through institutional Microsoft 365 A1, A3, or A5 accounts when the school’s IT administrator enables it. That means the core improvements — better essay drafts in Word, deeper spreadsheet analysis in Excel, more polished presentations in PowerPoint — could be accessible without paying anything extra.

The key caveat: the free A1 plan that most institutions use has historically provided limited in-app Copilot integration, so the depth of access varies widely by school and licensing tier. It’s worth checking with your institution’s IT office or library to find out exactly what Copilot features your account unlocks.

For students approaching graduation or already in the workforce, the bigger picture is worth keeping in mind. Copilot-powered tools are increasingly a baseline expectation in enterprise environments. Learning to work effectively with AI inside Word, Excel and PowerPoint now — not just using the apps in their traditional form — is increasingly what hiring managers mean when they ask about productivity software fluency. GPT-5.6 makes that AI layer meaningfully more capable. Getting comfortable with it before your first job is a practical head start.

Source: OpenAI