Musk v. Altman

Two of the founders of OpenAI are now in federal court fighting over what the company was supposed to be — and what it's allowed to become.

A decade after Elon Musk and Sam Altman helped found OpenAI as a nonprofit research lab, the two men are facing each other across a federal courtroom in Oakland. Musk alleges that Altman and OpenAI president Greg Brockman betrayed the lab's founding charitable mission by spinning its core technology into a for-profit business. OpenAI says Musk's lawsuit is a baseless attempt to hobble a competitor he failed to control.

Opening arguments began on April 28, 2026, with Musk's lead trial lawyer Steven Molo telling the nine-juror advisory panel that "without Elon Musk, there would be no OpenAI, pure and simple," according to CNBC's courtroom reporting. Of the 26 claims Musk originally asserted in 2024, only two remain at trial: breach of charitable trust and unjust enrichment. The fraud and constructive fraud claims were dismissed by Musk's own lawyers ahead of trial to streamline the case. Microsoft, OpenAI's largest commercial backer, is named separately on an aiding-and-abetting claim.

Because the case is being heard in equity, Judge Gonzalez Rogers — not the jury — will issue the binding ruling. The trial is scheduled to run roughly four weeks, with all evidence expected by May 21.

How we got here

The two sides

The legal question underneath

Beyond the personal feud, the case turns on a genuinely unsettled question of nonprofit law: when a donor gives money to a charity, what rights does that donor retain over how the charity later evolves? Musk's theory frames the case as a breach of charitable trust. Some legal scholars are skeptical that the framing maps cleanly onto how nonprofit law actually works, noting that OpenAI's nonprofit parent still exists and still controls the for-profit subsidiary.

California's attorney general — who would normally be the party with clearest standing to enforce a charitable trust — has declined to join Musk's suit, saying the office did not see how the action serves the public interest.

Who's expected to testify

• Elon Musk — Plaintiff. His testimony about what he was promised in 2015 is central to the case.
• Sam Altman — Defendant; OpenAI CEO.
• Greg Brockman — Defendant; OpenAI president.
• Satya Nadella — Microsoft CEO; relevant to OpenAI's commercial partnerships.
• Ilya Sutskever — Former OpenAI chief scientist and co-founder.
• Mira Murati — Former OpenAI CTO.

What a ruling could change

If Musk prevails, the most far-reaching remedies on the table would force OpenAI to unwind its for-profit structure and remove its current leadership. Even short of that, an adverse ruling — or a prolonged appeal — would cloud OpenAI's path to a public offering. Reporting suggests an IPO previously rumored for 2027 could slip to 2028 or later if the case extends through appellate review.

If OpenAI prevails, the company is positioned to continue its current trajectory: a roughly $500 billion–to–$1 trillion-valued enterprise, with a public benefit corporation operating under a nonprofit parent, and a path toward a stock listing.

Live coverage

Several major outlets are running live blogs that update through the trial day. The trial itself is closed to cameras; reporters file from inside the courtroom or an adjacent media room with an audio feed.

• CNBC — Live updates from inside the courtroom — Day-by-day reporting, including direct quotations from opening arguments.
• ABC7 San Francisco — Week 1 live blog — Local Bay Area coverage with running updates.
• MIT Technology Review — Ongoing trial coverage — Reporter Michelle Kim is filing through the trial.
• NBC News — What's at stake in the trial — Background on the case and witness list.
• NPR — Tech CEOs head to court over the fate of OpenAI — Audio reporting and explainer.
• CBC News — Trial overview — Includes pre-trial rulings on what Musk can and can't be questioned about.
• Axios — How OpenAI's Microsoft ties change as the trial begins — Focused on the Microsoft angle.

Primary documents and the IRS framework

For the actual court filings — the complaints, key orders, and the live federal docket — see The Docket. For the regulatory architecture beneath the case — the actual § 501(c)(3) statute, the Treasury regulations, the inurement prohibition, and where to find OpenAI's own Form 990 filings — see The Framework. Both pages link only to primary sources or major-outlet reporting.