Microsoft releases MAI-Thinking-1, its first reasoning model with 35B parameters

Microsoft launched seven AI models at its Build 2026 developer conference, including MAI-Thinking-1, the company's first reasoning model.

MAI-Thinking-1 specifications

The 35-billion-parameter model was trained on "enterprise-grade, clean and commercially licensed data," according to Microsoft. The company claims it beat Anthropic's Claude Sonnet 4.61 when evaluated by independent reviewers in blind tests, and matches Claude Opus 4.6's SWE Bench Pro benchmark score for coding. Specific benchmark numbers were not disclosed.

MAI-Thinking-1 is designed for multi-step agentic tasks and is available in private preview through Microsoft Foundry. Context window size and pricing have not been announced.

Six additional models

MAI-Code-1: A coding model Microsoft describes as "ultra-efficient" and "tuned for GitHub." Available today in Copilot and VS Code. No parameter count or benchmarks disclosed.

MAI-Image-2.5 and MAI-Image-2.5 Flash: Microsoft's first text-to-image and image-to-image models. According to Microsoft, MAI-Image-2.5 outperformed Nano Banana Pro on ELO ratings and ranked third on the LM Arena Leaderboard at launch, behind Nano Banana. Available now in PowerPoint, Foundry, and rolling out in OneDrive.

MAI-Transcribe-1.5: A speech transcription model supporting 43 languages, with streaming capabilities coming soon. This represents an update to the MAI-Transcribe line released just two months prior.

MAI-Voice-2 and MAI-Voice-2 Flash: Text-to-speech models supporting 15 more languages than the previous MAI-Voice-1, which was released in preview two months ago.

Microsoft AI CEO Mustafa Suleyman stated that all models include watermarking "from scratch" and offer cost efficiency improvements up to 10x compared to competitor models, though specific pricing was not provided.

Availability and healthcare partnership

All MAI models will be available through Fireworks AI (now generally available on Foundry), Baseten, and OpenRouter.

Microsoft also announced a partnership with Mayo Clinic to develop a frontier model for healthcare, joining existing medical AI efforts from OpenAI and Google. Microsoft already offers Copilot Health.

What this means

Microsoft's entry into reasoning models puts it in direct competition with OpenAI's o1 series, Anthropic's Claude family, and DeepSeek's R1. The emphasis on commercially licensed training data addresses enterprise customers' copyright concerns, though the lack of disclosed pricing and limited benchmark data makes performance comparisons difficult. The rapid release cycle—with voice and transcription model updates arriving just two months after initial previews—signals Microsoft's aggressive push to compete across the full AI model stack.