Microsoft shifts Copilot to MAI models

Microsoft is starting to replace some OpenAI and Anthropic models inside Copilot and Microsoft 365 with its own MAI systems as it tries to lower the cost of serving AI features at scale. Reports published on July 8 and July 9 said the shift has begun in products including Outlook and Excel, with users often seeing the same Copilot interface while the underlying model changes. The move comes weeks after Microsoft introduced a broader MAI model family at its Build 2026 conference. Mustafa Suleyman, Microsoft’s AI chief, has framed the effort in cost terms, saying outside models are expensive and that Microsoft wants to reduce those payments. ### Why is Microsoft changing the model behind Copilot now? Microsoft has been under pressure to make Copilot economics work across consumer and workplace products as usage grows. Bloomberg-republished reports said the company has begun swapping in MAI models for selected tasks in software products such as Excel and Outlook to reduce reliance on OpenAI and Anthropic and trim inference costs. Mustafa Suleyman said at Build that Microsoft’s plan is to “reduce and ultimately eliminate” spending on external AI models, according to PCMag’s report on July 8. PCMag said the comment referred specifically to money Microsoft pays Anthropic. ### Which Microsoft products are already using MAI? (finance.yahoo.com) PCMag reported that Microsoft 365 apps are increasingly favoring the company’s own models over ChatGPT and Claude in some workflows. Separate reports said Outlook and Excel are among the first visible examples of that routing change, while GitHub Copilot has already received at least one MAI coding model. (ca.pcmag.com) Microsoft said in its Build 2026 materials that MAI-Code-1 is available in Copilot and Visual Studio Code. In a keynote transcript published by Microsoft AI, the company described MAI-Code-1-Flash as an “inference efficient” coding model built for GitHub Copilot CLI and said it was designed to deliver strong coding performance at lower cost. (ca.pcmag.com) ### Does this mean Microsoft is cutting off OpenAI and Anthropic? Microsoft has not said it is ending its use of OpenAI or Anthropic across the board. The reporting describes a partial replacement in selected tasks, not a full withdrawal from outside models. (blogs.microsoft.com) Anthropic was only added more broadly to Microsoft 365 Copilot last year as part of Microsoft’s model-choice strategy. Microsoft said in a September 2025 blog post that customers could use Anthropic models in products such as the Researcher agent, which shows the company is now adjusting a strategy it had recently expanded. (finance.yahoo.com) ### What does this say about the AI business inside big software companies? Microsoft’s own language around MAI has emphasized efficiency as much as capability. In Build materials published in June, Microsoft described several MAI releases as practical and cost-conscious, including models tuned for coding, transcription, image generation and voice. (microsoft.com) The reporting around this week’s shift points to the same calculation. Technology and trade reports said Microsoft expects many users to notice little visible change when MAI replaces third-party models in the background, which suggests the company is judging some AI features by whether it can deliver similar output more cheaply. (microsoft.ai) ### What should readers watch next? Build 2026 is the clearest public marker for Microsoft’s next steps because that is where the company laid out the MAI family and identified Copilot, VS Code and the Microsoft stack as deployment targets. Future product notes for Microsoft 365 Copilot and GitHub Copilot will show whether more tasks move from OpenAI and Anthropic to MAI over the second half of 2026. (msn.com) (microsoft.ai)