# Microsoft finishes pre-training MAI-Base-2, a 2.8-trillion-parameter model

> Microsoft AI says MAI-Base-2 is an 80-billion-active, 2.8-trillion-total MoE, trained on 16k GB200s over 38 days. Weights are not out. Microsoft says it will license them to trusted partners through Foundry.

Published 2026-10-15T08:00:00-07:00 · Daily Digest · Canonical: https://news.littlewolflabs.com/posts/2026-10-15-microsoft-mai-base-2

On October 15, [Microsoft AI](https://microsoft.ai/news/frontier-pre-training-at-microsoft-ai/) said it has finished pre-training MAI-Base-2, an in-house mixture-of-experts model with 80 billion active parameters and 2.8 trillion total. Microsoft says it trained the run on 16k GB200 GPUs over 38 days in August and September 2026. [Mustafa Suleyman](https://x.com/mustafasuleyman/status/2110766651344146564) posted that post-training results are "coming soon."





These next lines are Microsoft's claims, from that post, not an independent bench. Microsoft says MAI-Base-2 outperforms every open-weight model it tested on held-out evaluations, scored as bits per byte, lower better. It says the recipe is 4.2 to 12.3 times more pre-training-FLOPs-efficient than DeepSeek-V4-Pro-Base. The opening summary rounds that to 4–12 times. Microsoft also says the pre-training uses organic data and does not distill from other models, and that it plans to license the weights to trusted partners through Foundry. Post-training is underway. There is no public weight, no API, and no price. [StreetInsider](https://www.streetinsider.com/Corporate+News/Microsoft+completes+pre-training+of+MAI-Base-2+AI+foundation+model/27192270.html) carried the completion.

## What it costs

Nothing to buy. Microsoft has not published a price for MAI-Base-2.

## Should you switch

No. There is nothing to call yet. It matters because Microsoft is training its own frontier base model rather than only serving OpenAI's. If a paid version ships, it lands on the [prices page](/pricing-limits) only if it clears the inclusion rule already printed there: within about 10 points of the Artificial Analysis Intelligence Index leader, or in the top 15 on LMArena text, and a published paid price.