Microsoft's first decision model returns a calibrated probability in 85 ms at $0.042 per million input tokens with free outputs — 35x faster than GPT-6 Sol and, in Microsoft's own Xbox labelling test, 200x cheaper at comparable quality.
Ask a general-purpose LLM to decide which team a support ticket belongs to and you wait for it to write the answer back, then pay for every token of that answer. Microsoft's new model does the same bounded job in a median 85 milliseconds, charges $0.042 per million input tokens, and charges nothing at all for output[1] — because it never generates prose in the first place.
On 9 October 2026 Microsoft announced Microsoft-Decision-1, a decision-scoring model available in Microsoft Foundry and through OpenRouter, in a post by Achint Srivastava, VP of Software Engineering in the Office of the CTO[1].
It is not a chat model, and that is the point. You hand it input text or JSON plus a fixed set of options; it returns a calibrated probability for each option through a structured API call — yes/no, multiple choice, rating scales, and rubric-based grading of AI output and agent actions[1]. Microsoft's deployment guide describes the difference plainly: unlike a generative LLM, the model "doesn't generate a free-form response or written rationale. It makes a focused judgment about text or JSON and returns a typed, numerical decision"[2].
Under the hood it is a small, repurposed open model. Microsoft post-trained Qwen3.5-9B for fast, single-pass decision scoring, and says it plans to rebase the service on other models, including its own MAI family and OpenAI's[1].
The numbers Microsoft published are its own, and they are specific. Across a 36-benchmark comparison covering 147,137 questions that were kept blind from training, Microsoft-Decision-1 posted an average accuracy of 83.5, ahead of Jev 1.13.0 at 82.3, Quyet-1.0-Large at 81.9, GPT-6 Luna Decisions at 79.4 and H2O-Lightning-4B at 77.2[1]. On speed it reports a median (p50) latency of 85 ms and a p95 of 125 ms — 2.5 times quicker than the runner-up, H2O-Lightning-4B v1.1, and 35 times quicker than GPT-6 Sol — measured against JevBench v1.6.1 adjusted median latency checked on 7 October, with Decision-1 measured through Foundry in the same region[1]. The post carries an editor's note saying it was later updated to add Jev's accuracy and calibration numbers[1].
Two properties matter more to builders than the leaderboard. First, stability: Microsoft perturbs the same request eight ways and counts how often the decision flips, reporting flips on just 1.3% of perturbations on average, and zero flips when option descriptions are paraphrased or options are reversed or shuffled[1]. Second, calibration: the probability is part of the API response, not an internal ranking, so Microsoft's stated contract is that a 90% prediction should be right about nine times out of ten on representative cases[1]. Safety testing covered 5,250 requests across 11 benchmarks spanning harmful content, jailbreak attempts and prompt injection[1].
Microsoft's internal pilots are where the cost claim comes from. Xbox Research sorted more than 10,000 open-ended feedback items into fixed research themes and found Decision-1 "competitive on quality with GPT-6 Sol while running over 14 times faster and 200 times less expensive"[1]. The Copilot team's quality-control testing found it competitive with GPT5.6 Luna and 100 times faster, and in Microsoft Discovery's adaptive replanning loop it was 46 times more consistent than the LLM-based score at three times the speed[1].
Pricing is the headline: $0.042 per million input tokens, output tokens free[1]. For comparison, OpenAI's Decisions API — in public beta, currently serving only gpt-6-luna, and pitched as about 10x faster than its Responses API — charges $0.10 per million input tokens with no output or cache charges[3]. Both companies are converging on the same shape: pay for evidence in, not prose out.
Most teams do not need a new model; they need to find the dozen bounded decisions buried inside a workflow that is currently being run by a general-purpose LLM — or by an intern. We map those decision points, pull a labelled sample from your own history, run it against the candidate models, and hand back the threshold table: at what confidence you automate, at what confidence a person looks, and what each choice costs you per thousand tickets.
If the answer turns out to be "your current setup is fine at your volume", we will tell you that too — with the numbers. Talk to us and we will run the evaluation on your data before you commit to anything.
Sources - Introducing Microsoft-Decision-1, our model for fast decision-making — Microsoft - Deploy and use Microsoft-Decision-1 in Microsoft Foundry — Microsoft Learn - Decisions API — OpenAI
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