Microsoft Debuts MAI-Thinking-1, Its First In-House Reasoning Model

Microsoft AI (@MicrosoftAI) unveiled MAI-Thinking-1, its first full-fledged in-house reasoning model, on June 2 during Build 2026. Built from scratch as a 35B active / ~1T total MoE model, it claims performance competitive with similar-sized models on STEM reasoning and coding tasks. The model scored 52.8% on the coding benchmark SWE-Bench Pro, matching Claude Opus 4.6, and reached 97% on the math reasoning benchmark AIME 2025 (Microsoft AI post, model page).