Microsoft plans to pay Anthropic more than $2 billion annually to use its Claude AI models inside Copilot, according to a report from The Information published on October 12, 2026. The plannedlay underscores how far Microsoft has moved from its earlier reliance on OpenAI models for the assistant — and how model access has become a major recurring operating cost that Microsoft now manages task by task rather than through a single supplier.

Why Microsoft went shopping outside the family

Copilot had a performance problem. Microsoft faced significant pressure from clients over the assistant's subpar results, particularly inside Microsoft Office applications — the flagship products where those enterprise customers expect Copilot to perform.

Microsoft responded by bringing Anthropic's models into Copilot in the summer of 2025, marking a clear break from the company's earlier preference for OpenAI models, which it had previously been able to access at no additional cost under their substantial partnership.

The internal push came from Charles Lamanna, Microsoft's Executive Vice President of Copilot. Lamanna demonstrated that Claude models significantly improved output on specific tasks, including financial automation in Excel and building presentations in PowerPoint.

The numbers behind the bet

Corporate Copilot users now number more than 30 million, a figure that has more than doubled since the beginning of 2026. Microsoft now pairs Claude with OpenAI's models across Word, Excel, Outlook, and PowerPoint — a multi-model setup in which model choice directly shapes both output quality and cost.

Cost has been a recurring concern. Microsoft's internal spending on Anthropic had reached roughly $1 billion on an annualized basis earlier in 2026, and the company subsequently cut that spending by more than 33%. The main tool for managing the bill is an in-house model router, which selects the most economical AI model for each task and sends a given request to whichever model can handle it at the lowest cost. According to the report, Microsoft is increasingly using OpenAI models through this setup to save costs and improve margins — with Anthropic's models kept for the work where their output justifies their premium.

A complicated web of partners

Microsoft remains OpenAI's largest partner. At the same time, it has become a major customer of Anthropic, in a relationship that includes up to $5 billion from Microsoft to Anthropic and a $30 billion commitment tied to Azure services — financial ties that bind the companies together even as Anthropic and OpenAI compete to do the work inside Microsoft's own assistant.

Lamanna's role in the shift has raised his profile internally. Initial worries about the financial impact of Anthropic's premium pricing did not deter him, and his advocacy has positioned him favorably with Microsoft's senior leadership. The Information's reporting noted speculation about his potential to one day succeed Satya Nadella as CEO.

What this means for Microsoft, OpenAI, and Anthropic

The arrangement captures Microsoft's balancing act: invest in Anthropic, pay a premium for its models only where their output justifies it, and lean on OpenAI's cheaper models for much of the daily workload — all while remaining OpenAI's largest partner.

Microsoft has already shown it is willing to cut Anthropic spending sharply when costs run high, as the reduction of more than 33% earlier in 2026 demonstrated. The final figure will depend on how Copilot usage grows and how aggressively the router shifts work toward cheaper models — the mechanism that, in effect, will determine how the planned $2 billion actually gets spent.