Microsoft invested about $13B in OpenAI between 2019 and 2023, and after the October 2025 restructuring it holds a roughly 27% economic stake worth approximately $135B — but it does not control the company and no longer has the exclusive cloud or unilateral AGI terms it started with.
That is the short answer. The longer answer is more interesting, because almost every headline number in this deal — the $13B, the 49% you may have read, the AGI "escape hatch" — has either changed or was never quite what it seemed.
Microsoft–OpenAI Deal Terms, Explained
The Microsoft–OpenAI deal terms grant Microsoft a roughly 27% economic stake in OpenAI Group PBC in exchange for about $13B in cumulative investment, along with IP rights to OpenAI's models through 2032, a revenue-sharing arrangement running until 2030, and a right of first refusal on new compute. In return, OpenAI committed to buying roughly $250B of additional Azure services. Microsoft has no governance control.
If you only remember one thing, remember this: Microsoft's money bought economics and IP access, not ownership. The nonprofit OpenAI Foundation still controls the company. That distinction is the whole story, and it is why this was structured as one of the strangest large investments in corporate history rather than a clean acquisition.
The Microsoft–OpenAI Deal Terms, Tranche by Tranche
The $13B was never a single check. It arrived in three waves, and a large portion of each was Azure compute credits rather than cash — capital that flowed right back to Microsoft as cloud revenue.
| Year | Amount | Form | What It Bought |
|---|---|---|---|
| 2019 | $1B | Cash + Azure credits | Exclusive cloud partnership, early model access |
| 2021 | ~$2B est. | Azure credits | Deepened compute commitment for GPT-3 era |
| 2023 | ~$10B | Cash + Azure credits | Capped-profit stake up to ~49% of profits, GPT-4 scale |
| 2025 | Restructured | Equity conversion | ~27% stake in new PBC, ~$135B paper value |
| Through 2030 | Revenue share | Ongoing | Percentage of OpenAI revenue back to Microsoft |
| Through 2032 | IP rights | Ongoing | Access to models, weights, and post-AGI tech |
The "49%" figure that circulated for years referred to Microsoft's share of OpenAI's profits under the capped-profit model, not equity ownership — and even that was capped at a multiple of the investment. The 2025 restructuring replaced this with conventional equity.
What the 2025 Restructuring Changed in the Deal Terms
In October 2025, OpenAI converted its capped-profit subsidiary into OpenAI Group, a Delaware public-benefit corporation, and renegotiated the entire Microsoft relationship. The headline outcomes:
Microsoft stake: ~27%
Converted from capped-profit interest to ~$135B in equity of the new PBC
Foundation control: ~26% + governance
The nonprofit parent keeps voting control and a ~$130B economic stake
Azure exclusivity ended
Replaced by a right of first refusal on new compute, not a lock-in
IP rights extended to 2032
Up from 2030, now explicitly covering models past an AGI declaration
AGI verified by an expert panel
OpenAI's board can no longer unilaterally declare AGI to cut Microsoft off
$250B Azure commitment
OpenAI agreed to buy incremental Azure services as part of the deal
Both sides gave something up. Microsoft surrendered exclusivity and its unilateral leverage over the AGI clause; OpenAI surrendered the option to ever fully walk away from Microsoft's IP rights, which now extend two years longer and survive the very event — AGI — that was once supposed to end them.
What Happens to the Deal at AGI
This was the clause that made the original contract famous. OpenAI's charter defines AGI as "highly autonomous systems that outperform humans at most economically valuable work," and the 2019–2023 agreements said that once OpenAI's board declared AGI had been achieved, that technology fell outside Microsoft's license. In effect, the board held a switch that could strand Microsoft's biggest AI bet at the worst possible moment.
The 2025 deal defused it three ways. First, an AGI declaration now requires verification by an independent panel of experts rather than a board vote alone — removing the conflict of interest. Second, Microsoft's IP rights were explicitly extended to cover models developed after any AGI declaration, through 2032. Third, the revenue-share and access provisions continue regardless of the AGI determination. The escape hatch still exists on paper, but Microsoft now keeps its seat at the table even if someone pulls the lever.
For investors tracking AI valuations, this is the most consequential change. The old AGI clause was an uninsurable tail risk sitting on top of Microsoft's ~$13B exposure. Removing it is arguably worth more than the equity reshuffle.
Who Got the Better End of the Deal Terms?
What Microsoft Won
- ✓ ~27% stake now marked near $135B on a ~$13B basis
- ✓ Model IP rights locked in through 2032
- ✓ AGI tail risk neutralized by independent verification
- ✓ ~$250B in committed incremental Azure revenue
- ✓ Copilot and Azure AI built on frontier models it co-owns
What Microsoft Gave Up
- ✕ Azure exclusivity — OpenAI signed ~$300B with Oracle
- ✕ Any governance control; the Foundation still runs OpenAI
- ✕ Leverage from the old unilateral AGI cutoff
- ✕ The simplicity of a capped-profit structure it understood
On balance, Microsoft won. A ~10x paper markup on $13B, durable IP rights, and a removed tail risk outweigh the loss of exclusivity — especially since OpenAI still committed a quarter-trillion dollars back to Azure. OpenAI got something it valued more than any single term: the freedom to multi-source compute at the scale its AI spending now demands, where no single provider can supply enough GPUs.
Why the Deal Terms Matter Beyond These Two Companies
The Microsoft–OpenAI structure became the template — and the cautionary tale — for every big-tech-meets-AI-lab deal that followed. Amazon and Google both invested in Anthropic (roughly $8B and $3B+ respectively) using convertible and equity structures that deliberately avoided OpenAI's capped-profit and AGI complexity. Regulators in the US, UK, and EU spent two years probing whether the arrangement amounted to a de facto merger; the 2025 move to a cleaner equity stake without board control was partly a response to that scrutiny.
The lesson for founders and funds: when you take strategic capital from a hyperscaler, the cloud commitment, IP license, and exclusivity clauses can matter more than the valuation. Microsoft's real return on OpenAI was never just the equity mark — it was the compute revenue, the model access, and the distribution into Office and Azure. Strategic money is rarely just money.
Microsoft put in ~$13B and walked away with a ~$135B stake, model IP through 2032, and the AGI escape hatch defused.
It bought economics and access — not control. And in AI, that may have been the smarter thing to own.
Track AI company valuations and big-tech AI exposure on the AI Valuations Dashboard at Value Add VC. Originally published in the Trace Cohen newsletter.