Microsoft Replaces OpenAI and Anthropic With Internal AI Models Across Workplace Apps

Summary

Microsoft is systematically replacing AI models from OpenAI and Anthropic with its own internally-built MAI models across multiple workplace applications, including Excel, Outlook, Copilot, Teams, and GitHub Copilot. According to sources, tens of thousands of AI prompts are now completed weekly using Microsoft's internal models in widely-used spreadsheet and email applications, a significant shift from the company's previous heavier reliance on external AI providers.

The strategic move is driven by Microsoft's efforts to reduce substantial AI costs as token consumption grows exponentially across products like its workplace assistant Copilot. While OpenAI partnership discounts remain in effect for now, Microsoft's AI leadership has explicitly stated the goal is to "reduce and ultimately eliminate" spending on Anthropic and other external providers. In June, AI chief Mustafa Suleyman announced that Microsoft had developed new models capable of matching Anthropic's popular Opus 4.6 model at significantly reduced costs.

Although internal MAI model usage still represents a small share of overall AI consumption, the move signals Microsoft's confidence in its AI capabilities and intent to reduce vendor dependency. The company plans to expand internal model deployments, with Suleyman indicating that a Microsoft-built transcription model will soon power Teams and other products. This initiative reflects a broader industry trend of major tech companies developing proprietary AI to control costs and achieve independence from external AI labs.

• Microsoft's internal models have demonstrated competitive performance, matching Anthropic's popular Opus 4.6 model at lower costs
• The shift reflects a broader industry trend of major tech companies building proprietary AI to reduce vendor lock-in and control expenses