Who owns OpenAI?
OpenAI is controlled by a nonprofit, the OpenAI Foundation, which appoints and can remove the entire board of the for-profit OpenAI Group PBC. After the recapitalization completed October 28, 2025, the Foundation holds roughly 26% of the equity, Microsoft roughly 27%, and employees and other investors roughly 47%.
Why — the first-principles explanation
OpenAI's ownership is strange because control and equity were deliberately separated. Most companies fuse them: own the most shares, pick the board. OpenAI split them on purpose.
OpenAI started on December 8, 2015 as a pure nonprofit, co-founded by Sam Altman, Elon Musk, Ilya Sutskever, Greg Brockman, and others. The problem showed up fast: training frontier models costs billions, and nonprofits cannot sell equity. So OpenAI bolted a for-profit arm onto the nonprofit. Investors could put money in and share the upside, but the nonprofit board still ran things. That structure is what let the board fire Sam Altman in November 2023 — and it's what got renegotiated afterward. The recapitalization completed on October 28, 2025 cleaned it up. The for-profit became OpenAI Group PBC, a Delaware public benefit corporation — a company legally allowed to weigh its mission against shareholder returns. The nonprofit was renamed the OpenAI Foundation, took a conventional equity stake of about 26%, and kept the thing that actually matters: it appoints every director of OpenAI Group PBC and can remove them at any time. Microsoft, which has funded OpenAI since 2019, holds about 27% — a bigger slice than the Foundation, with no matching control. Employees and other investors hold roughly 47%.
This wasn't purely OpenAI's choice. Because the nonprofit's assets are charitable assets, state attorneys general had jurisdiction. California's AG ran an investigation for about 18 months and signed a memorandum of understanding with OpenAI on October 27, 2025 — one day before the deal closed — extracting commitments that the nonprofit retain control of the PBC, that safety be prioritized, and that OpenAI stay headquartered in California. Delaware's AG negotiated in parallel.
So the useful answer: Microsoft owns the most, the Foundation controls the most. Nobody owns OpenAI outright, and Sam Altman, unusually for a CEO of a company this size, has historically held no significant equity stake.
An example that makes it click
Picture a family restaurant. Your uncle put in most of the cash — he owns 27% of the business and gets 27% of the profits. Grandma put in less and owns 26%. But when the family wrote the rules, they gave Grandma one specific power: she alone picks the managers, and she can fire any of them, any day, for any reason.
Uncle is richer. Grandma is in charge. That's OpenAI. Microsoft is the uncle, the OpenAI Foundation is Grandma, and the state attorney general is the lawyer who read the contract before anyone signed and made Grandma's veto stick in writing.
Key facts
- OpenAI's recapitalization completed October 28, 2025, converting the for-profit arm into OpenAI Group PBC, a Delaware public benefit corporation, and renaming the nonprofit the OpenAI Foundation.
- Equity split after the recapitalization: OpenAI Foundation about 26%, Microsoft about 27%, employees and other investors about 47%.
- All directors of OpenAI Group PBC are appointed by the OpenAI Foundation, which can remove them at any time.
- California Attorney General Rob Bonta executed a memorandum of understanding with OpenAI on October 27, 2025, after roughly 18 months of investigation, securing commitments on nonprofit control, safety, and remaining headquartered in California.
- OpenAI was founded December 8, 2015 by Sam Altman, Elon Musk, Ilya Sutskever, Greg Brockman, Trevor Blackwell and others.
- In April 2026 OpenAI closed a $122 billion funding round at an $852 billion post-money valuation; in June 2026 it confirmed an SEC filing toward an IPO, with no committed timeline.
▶ The 60-second explainer (script)
Who owns OpenAI? The answer splits into two, and the split is the whole point. On equity: Microsoft owns about twenty-seven percent. The OpenAI Foundation — that's the nonprofit — owns about twenty-six. Employees and other investors own the remaining forty-seven. So Microsoft is the biggest single shareholder. But on control: the OpenAI Foundation appoints every single director of OpenAI Group PBC, and can remove any of them at any time. Microsoft can't. So Microsoft owns more and controls nothing. Here's how that happened. OpenAI started in December 2015 as a nonprofit. Then it turned out that training frontier AI costs billions, and nonprofits can't sell shares. So they bolted a for-profit onto it. That awkward structure is what let the board fire Sam Altman back in 2023. On October 28th, 2025, they finished cleaning it up: the for-profit became a public benefit corporation, the nonprofit became the OpenAI Foundation, and the Foundation kept board control. And this wasn't just their decision — the nonprofit's money is charitable money, so state attorneys general had a say. California's AG investigated for about eighteen months and signed an agreement the day before the deal closed, locking in nonprofit control, safety commitments, and that OpenAI stays in California. Bottom line: Microsoft owns the most. The Foundation runs the place.
What authoritative sources say
People also ask
Does Microsoft own OpenAI?
No. Microsoft is the largest single shareholder at roughly 27% as of the October 2025 recapitalization, but it appoints no directors and does not control the company. The OpenAI Foundation appoints the entire board.
Does Elon Musk own part of OpenAI?
No. He co-founded it in 2015 and donated to the nonprofit, but he left the board in 2018 and holds no equity. He later sued OpenAI over the for-profit conversion and founded a competitor, xAI.
How much of OpenAI does Sam Altman own?
Altman has historically held no significant direct equity stake in OpenAI, which is unusual for a CEO of a company this size. Any change would appear in IPO filings.
Is OpenAI publicly traded?
Not as of July 2026. OpenAI confirmed in June 2026 that it had filed with the SEC toward an IPO, but leadership indicated the listing timeline is uncertain. You cannot buy OpenAI shares on a public exchange today.
Is OpenAI still a nonprofit?
Partly. The OpenAI Foundation is a nonprofit and controls the group. The operating company, OpenAI Group PBC, is a for-profit Delaware public benefit corporation that can raise capital and pay returns to shareholders.