Musk v. Altman was a lawsuit brought by Elon Musk (joined by xAI) against OpenAI, Inc., OpenAI L.P., Sam Altman, Greg Brockman, and Microsoft Corporation, alleging that OpenAI's founders breached promises to keep the lab a nonprofit dedicated to benefiting humanity. The case went to trial in the U.S. District Court for the Northern District of California (Oakland) in April–May 2026, where Musk sought up to $150 billion in damages, the ouster of Altman and Brockman, and the unwinding of OpenAI's for-profit conversion. On May 18, 2026, a unanimous nine-juror advisory verdict dismissed all of Musk's claims, and Microsoft's aiding-and-abetting exposure, on statute-of-limitations grounds, and Judge Yvonne Gonzalez Rogers adopted the verdict and entered judgment for the defendants.
Background
OpenAI was founded in 2015 as a nonprofit by Musk, Altman, Brockman, Ilya Sutskever, and others, framed as a hedge against the concentrated power of for-profit AI labs. Musk left OpenAI's board in 2018 after disagreements with Altman and Brockman about the lab's direction, including a failed attempt to merge OpenAI into Tesla. After 2018, OpenAI established a for-profit subsidiary and became the dominant frontier-AI lab (OpenAI), valued at more than $850 billion as of April 2026.
Musk filed an initial state-court suit in February 2024, later refiling in federal court in August 2024 (https://storage.courtlistener.com/recap/gov.uscourts.cand.433688/gov.uscourts.cand.433688.32.0_1.pdf). A 26-claim amended complaint followed in November 2024. In January 2026 Musk's attorneys quantified the damages claim at up to $134 billion. In February 2026 a separate xAI v. OpenAI trade-secrets case was dismissed by a federal judge in California, and xAI/SpaceX merger materials valued the combined entity at $1.25 trillion. In April 2026 Musk sought the ouster of Altman and Brockman as part of his requested remedies (Source: cnbc.com).
Claims and theory of the case
Musk advanced a "promise-of-nonprofit" theory: that OpenAI's founders represented to him that the lab would remain a nonprofit in perpetuity and would advance AI for the benefit of humanity rather than for profit-driven tech giants. Musk alleged that OpenAI's conversion to a for-profit subsidiary structure, and its 2025 recapitalization preserving a nonprofit-with-controlling-stake structure, breached that promise, and that he was "assiduously manipulated" and "deceived" into making early contributions of money and reputation under false pretenses. Microsoft was named for aiding and abetting OpenAI's alleged misconduct on the charitable-trust claim.
The remedies Musk sought were up to $134 billion in damages (a figure that varied during the litigation, discussed below), an order to "unwind OpenAI's for-profit conversion and restructuring," the removal of Altman and Brockman, and the return of any "ill-gotten gains" to OpenAI's nonprofit rather than to Musk personally.
OpenAI characterized the lawsuit as "baseless" and as "a harassment campaign that's driven by ego, jealousy and a desire to slow down a competitor," and raised a statute-of-limitations defense. Microsoft denied aiding and abetting.
On April 24–25, 2026, on the eve of trial, Musk moved to dismiss the fraud and constructive-fraud claims to "streamline the case," and Judge Gonzalez Rogers granted the request. That left two of the original 26 claims to go to the jury: unjust enrichment and breach of charitable trust (Source: fortune.com; Source: wsau.com).
Procedural posture
Judge Yvonne Gonzalez Rogers (an Obama appointee who previously presided over Epic Games v. Apple) bifurcated the trial into a liability phase and a remedies phase, the latter scheduled to begin May 18, 2026 if liability were found. The jury's verdict was advisory, with Gonzalez Rogers making the final decision in both phases. The panel comprised nine jurors with no alternates. Time was allocated at roughly 20 hours each to Musk and OpenAI and 5 hours to Microsoft. Gonzalez Rogers stated the statute-of-limitations gating directly: "If the jury finds that Musk failed to file his action within the statute of limitations, it is highly likely that the Court will accept that finding and direct verdict to the defendants." The disclosed witness list included Musk, Altman, Brockman, and Microsoft CEO Satya Nadella (Source: cnbc.com).
Trial
Jury selection and opening
The federal jury was seated April 27, 2026 in N.D. Cal. (Oakland), with Altman and Brockman in attendance; Musk amplified Ronan Farrow's New Yorker exposé on Altman the same day on X. The liability phase was scheduled to conclude by May 21, 2026 (per an April 28 update), with court in session 8:30 AM–1:40 PM PT, Monday–Thursday. Per an April 28 disclosure, the nine-juror panel consisted of seven women and two men, including six immigrants and a former Lockheed Martin program manager. The April 28 witness list named Satya Nadella, Ilya Sutskever (former OpenAI Chief Scientist), and Mira Murati (former OpenAI CTO), in addition to Musk, Altman, and Brockman (Sources: aidisruption.ai; theinformation.com; cnbc.com; bigtechnology.com; wired.com).
On April 28 Musk took the stand and told jurors that Altman and Brockman "stole a charity," warning of a "Terminator outcome" if AI were controlled by ordinary companies. He said he was seeking $150 billion in damages, and also said in opening that "I was not averse to a small for-profit," a concession the OpenAI defense seized on. The Verge characterized the opening testimony as "unfocused and uncharming," with Musk appearing "more petty than prepared." OpenAI lawyer William Savitt countered that "we're here because Mr. Musk didn't get his way at OpenAI" (Sources: bloomberg.com; theverge.com).
The Wall Street Journal on April 27, 2026 characterized the dispute as a $180 billion fight, higher than the $134 billion figure cited at filing; the larger number reflected an updated valuation of the nonprofit-asset transfer Musk sought to unwind, with the proceeds directed back to OpenAI's nonprofit parent rather than to Musk personally (Source: wsj.com).
Also on April 28, Gonzalez Rogers ordered Musk, Altman, and Brockman to stop posting about the case on social media for the trial's duration, after Musk amplified the Farrow exposé and the parties had traded public barbs for months (Source: bloomberg.com). The same day she scolded OpenAI for taking inconsistent positions on the origin of its name (Source: theverge.com).
Musk's testimony and admissions
Musk returned to the stand on April 29, 2026, telling the court he was "a fool" for backing OpenAI and accusing Altman and Brockman of manipulating him into donating tens of millions of dollars to the lab (Source: wsj.com). Wired framed Musk's emerging trial narrative as "how Musk squeezed OpenAI" (April 30, 2026 newsletter brief). Gary Marcus and others noted that if the trial became a referendum on Musk personally rather than on OpenAI's organizational conduct, the legal outcome might not reflect the underlying governance question, and that OpenAI's founders had made explicit commitments to nonprofit status in public statements and legal filings, including a 2017 video by Altman, before later departing from them (Source: garymarcus.substack.com).
On April 30 Musk testified, and reaffirmed under cross-examination on May 1, that xAI "partly" distilled OpenAI models to train its own systems, telling the court "generally A.I. companies distill other A.I. companies." The admission came one week after the White House publicly condemned alleged Chinese-lab distillation attacks, drawing a parallel between xAI's training methodology and the Chinese-lab targets of US export-control policy. Musk also conceded he did not know what an AI safety card was (Sources: wired.com; techcrunch.com). OpenAI's counsel introduced internal 2017 emails showing Musk demanding majority voting control over OpenAI's co-founders, withholding promised funding, and trying to poach researchers, repositioning the dispute as Musk's own bid for control (Source: wired.com). In his April 29 testimony Musk described his 2017 cessation of $5 million-per-quarter donations as suspicion-based rather than a breach: "Thinking someone might steal your car is not the same as if someone has stolen your car."
Evidentiary rulings on AI risk
On April 30 Judge Susan Illston ruled that the trial would not address whether AI poses an existential threat: "I suspect that there are a number of people who do not want to put the future of humanity in Mr. Musk's hands. But we're not going to get into that." The ruling kept the dispute on charitable-trust and unjust-enrichment grounds (Source: nytimes.com).
On May 4 Gonzalez Rogers excluded the existential-risk testimony of Musk's only AI expert witness, Stuart Russell, from the jury after OpenAI objections; Russell, testifying at a $5,000-per-hour rate after 40-plus hours of preparation, had addressed cybersecurity, misalignment, and AGI winner-take-all dynamics. The exclusion compounded the April 30 Illston ruling (Source: techcrunch.com).
Settlement messages and pre-trial texts
Per a filing OpenAI's lawyers made on May 3, 2026, Musk messaged OpenAI President Greg Brockman on or about April 25, 2026, two days before trial, proposing settlement and then warning that "by the end of this week, you and Sam will be the most hated men in America" (Source: theinformation.com). On May 4 Gonzalez Rogers denied admission of the "most hated men in America" text as evidence, though OpenAI's lawyers had already filed it on the public docket (Source: cnbc.com). The Information's May 3 briefing reported that Brockman was scheduled to testify Monday, May 4, with Altman expected later in the week (Source: theinformation.com).
Brockman's testimony
Greg Brockman testified on May 4, 2026 that his OpenAI stake was then worth roughly $30 billion, prompting a Musk attorney to ask why he had not donated $29 billion to OpenAI's nonprofit arm. Musk attorney Steven Molo first had Brockman confirm he had not put any of his own money into early OpenAI before extracting the stake admission (Source: theinformation.com). Cross-examination also surfaced Brockman's financial ties to Altman: a stake in Altman's family office (gifted in 2017, then worth $10 million) plus shares in Altman-backed Cerebras and Helion Energy. An in-court email from Musk family-office head Jared Birchall warned that the arrangement meant "Greg is going to have a greater allegiance to Sam" (Sources: bloomberg.com; reuters.com).
On May 5, 2026 Brockman testified that OpenAI expected to spend $50 billion on computing in 2026, up from $30 million in 2017, and told jurors Musk "did not — and I believe does not — know AI." He recounted Musk demanding a majority stake and "$80 billion" during for-profit conversion talks because Musk needed it "to start a city on Mars," and that when Brockman pushed back Musk said he could start another AI company tomorrow with "one Tweet." Brockman further testified that he learned from public reporting that OpenAI board member Shivon Zilis's twins were fathered by Musk, after she had described the relationship as "platonic" (Sources: bloomberg.com; platformer.news). In further cross-examination reported May 10, Brockman testified that he stopped writing in his personal journal about OpenAI in 2023, and aggressive questioning explored his multi-billion-dollar equity stake and OpenAI's nonprofit origins (Source: theinformation.com).
Altman, Sutskever, and OpenAI insider testimony
Sam Altman testified for hours on May 12, telling the court that Musk had abandoned the OpenAI co-founders and worked to undermine the venture, and faced cross-examination over what Musk's attorney called a "pattern of lying." Altman testified that in 2017 Musk had demanded complete control of a proposed for-profit OpenAI arm and mused about passing it to his children (Source: bloomberg.com).
Ilya Sutskever testified during the week of May 11 that his OpenAI stake was worth roughly $7 billion (up from $5 billion in November), and that he had spent about a year gathering evidence of Altman's conduct, including "undermining and pitting executives against one another" (Sources: theinformation.com; click.mail.fortune.com).
OpenAI's former CTO Mira Murati testified by video deposition on May 6, 2026 that Altman lied to her by claiming OpenAI's legal department had cleared a new GPT model from going through the deployment safety board; she said general counsel Jason Kwon's account contradicted Altman's, and she sent the model through the board anyway (Source: theverge.com). In a Helen Toner deposition shown the same day, Toner stated that Altman told the board three GPT variants had been submitted to the deployment safety board when only one had (Source: courthousenews.com).
Shivon Zilis, mother of four of Musk's children and an OpenAI board member from 2017 to 2023, testified on May 6, 2026 that she resigned because Musk launched xAI. She also testified that Musk once offered Altman a Tesla board seat during early-OpenAI talks about OpenAI joining Tesla as the basis for a Google DeepMind–rivaling AI division; a contemporaneous Zilis email shown at trial said Altman seemed more open than the other co-founders and that Musk thought he could convince him (Sources: courthousenews.com; theinformation.com).
Across the May 4–7 testimony, OpenAI used current and former insiders (Brockman, Murati, Zilis, Toner) to raise questions about Altman's credibility, while the Musk-side narrative drew on the excluded Russell testimony, the excluded "most hated men" text, and Musk's distillation and "fool" admissions. Legal observers told The Information on May 10 that Musk's case was faltering because witnesses had failed to substantiate the "stolen charity" narrative (Source: theinformation.com).
Expert testimony on the nonprofit
Musk's nonprofit-law expert, David Schizer (a former Columbia Law School dean), testified on May 7, 2026 that OpenAI's charitable arm should have "a lot more" than its then-current roughly $200 billion, arguing the foundation should not have ceded technology and profit rights to Microsoft. OpenAI's lawyer noted that Musk's team paid Schizer $1,500 per hour for hundreds of hours of preparation (Source: theinformation.com).
Microsoft testimony and emails
Satya Nadella testified on May 11 that Musk never contacted him about concerns over Microsoft's OpenAI investments before or during the 2019 and 2023 deals: "We have each other's phone numbers." Nadella defended Microsoft's $13 billion investment as having borne "all the risk" after Musk left OpenAI's board in 2018, and confirmed that the nonprofit had approved the for-profit's creation (Sources: theinformation.com; implicator.ai).
Microsoft executive Michael Wetter testified on May 13 that Microsoft would have spent more than $100 billion on its OpenAI partnership by the end of its June fiscal year, including the $13 billion investment and infrastructure costs (Source: bloomberg.com).
Internal Microsoft emails released May 7–8, 2026 showed CEO Satya Nadella, EVP Jason Zander, CTO Kevin Scott, and chief scientific officer Eric Horvitz expressing skepticism about funding OpenAI in 2017–2018, roughly eighteen months before Microsoft's $1 billion investment. Kevin Scott complained the lab treated Microsoft like "a bucket of undifferentiated GPUs," and Jason Zander warned of a worst case in which OpenAI would "ditch Azure for AWS" and "bad-mouth us on the way over." The emails were the first public record of pre-investment Microsoft executive views on OpenAI and provided context for the April 27, 2026 Microsoft restructure that ended the AGI-IP-transfer clause and converted the license to non-exclusive (Source: wired.com).
Other trial developments
OpenAI was valued at $852 billion in trial materials, against the $850 billion-plus figure the company had publicly cited (Sources: cnbc.com; transformernews.ai). The damages ask varied across sources: the WSJ sized the suit at $130 billion on April 30 and at $180 billion on April 27; Wired and Transformer used the $134 billion original filing figure; and Musk's in-court framing on April 28 was $150 billion. The court did not authoritatively settle the figure.
A Financial Times analysis by Simon Mundy the week of May 13 treated the trial as the end of the nonprofit-AI ideal, surfacing a 2015 Altman email proposing a "Manhattan Project for AI" because "if it's going to happen anyway, it seems like it would be good for someone other than Google to do it first," and a 2017 email from Sutskever to Musk on the GPU-scale shift that made nonprofit-versus-corporate parity infeasible. Mundy wrote that "all three [Musk, Altman, Brockman] have joined Google in chasing AGI through profit-seeking corporate structures" (Source: ft.com).
Separately, on May 4 Musk settled the SEC's Twitter-disclosure suit for a $1.5 million civil fine without admitting wrongdoing, keeping the roughly $150 million he allegedly saved by delaying his 2022 Twitter-stake disclosure; the SEC had originally sought $200 million (Source: reuters.com). Musk also flew to China with President Trump's delegation on May 13, 2026, despite Gonzalez Rogers declining to excuse him from his ongoing trial (Source: nbcnews.com).
Verdict and current status
The trial ran 11 days of testimony and arguments. On May 18, 2026, after less than two hours of deliberation, a unanimous nine-juror advisory verdict dismissed all of Musk's claims against OpenAI, Altman, Brockman, and Microsoft on statute-of-limitations grounds. Gonzalez Rogers adopted the verdict and dismissed the case, noting from the bench: "There's a substantial amount of evidence to support the jury's finding, which is why I was prepared to dismiss on the spot." Microsoft's aiding-and-abetting claim was dismissed on the same untimely-filing reasoning; a Microsoft spokesperson said "the facts and the timeline in this case have long been clear and we welcome the jury's decision to dismiss these claims as untimely." Musk's lawyer reserved the right to appeal, but the judge suggested he might face an uphill battle because whether the statute of limitations ran out before Musk sued was a factual issue (Sources: reuters.com; npr.org).
Because the jury decided on timing, it did not reach the merits of whether OpenAI's pivot from its original nonprofit mission was legitimate. Gary Marcus argued the same day that the verdict "leaves those substantive questions permanently unanswered," writing that the procedural ending meant no federal jury had ruled on the substantive charitable-trust theory (Source: garymarcus.substack.com). Marcus forecast that the substantive merits of OpenAI's for-profit conversion would remain legally untested through at least the end of 2027, in the sense that no federal court would have ruled on them under charitable-trust or unjust-enrichment theories.
Commentary and consequences
Observers framed Musk v. Altman as the first jury-tested challenge to nonprofit-AI-mission promises. A liability finding on the breach-of-charitable-trust claim would have set precedent for how nonprofit-to-for-profit conversions are policed when founders allege the original mission was abandoned, and could have applied to other AI labs with nonprofit components (Anthropic, by contrast, was a public-benefit corporation from inception). The statute-of-limitations resolution materially weakened any precedential value: the case decided on timing rather than on the merits.
The verdict's most direct documented effect concerned OpenAI's planned public offering. OpenAI was targeting a Q4 2026 IPO at a valuation above $850 billion (per Sarah Friar's framing), a plan confirmed by OpenAI's confidential IPO filing with a potential valuation near $1 trillion; the company had flagged the Musk litigation as a business risk in its investor materials. Per the May 18 Reuters write-up, Wedbush analyst Dan Ives and OpenAI's own lawyers said the verdict removed a significant obstacle to that IPO (Sources: cnbc.com; reuters.com). On the adversary side, SpaceX filed its S-1 the evening of May 20, 2026, two days after the verdict, recast as an AI-first company with mid-June 2026 expected timing at a targeted valuation above $1.5 trillion; the two adversarial AI IPOs sat on the same six-week runway (see xAI for the SpaceX S-1 summary).
Commentators also noted Microsoft's rare board-level exposure as a defendant on AI-governance grounds, and that a liability finding plus court-ordered restructuring would have compounded the operational strain Lila Shroff described in an Atlantic piece on OpenAI (OpenAI).
Adjacent litigation
- xAI v. OpenAI (antitrust, Texas). Filed in 2025 by xAI and X (formerly Twitter), alleging anticompetitive behavior; a hearing was scheduled for May 2026.
- xAI v. OpenAI (trade secrets, N.D. Cal.). Dismissed February 2026.
- Garcia v. Character.AI (Garcia v. Character Technologies, Inc.); Raine v. OpenAI (Raine v. OpenAI, Inc.); NYT v. OpenAI/Microsoft (NYT v. Microsoft, OpenAI et al.) — related but separate exposure for OpenAI.
Personal context
Musk and Altman were once close friends. Public exchanges in late 2025 and 2026 included Musk on X in August 2025 ("Scam Altman lies as easily as he breathes") and Altman on X in February 2026 ("Really excited to get Elon under oath in a few months, Christmas in April!").
Relationships
- litigates: OpenAI, Sam Altman, Elon Musk, Microsoft.
- related: AI Acquihires (a different version of the same nonprofit-versus-equity-extraction concern), Raine v. OpenAI, Inc., AI Industry Lobbying — The 2025-2026 Political Offensive (Musk's xAI as the principal industry-adjacent counter-actor to OpenAI), Circular Financing in AI.
- contradicts: OpenAI's framing of itself as a mission-preserving nonprofit-controlled entity; Musk's complaint articulated the mission-drift critique in legal form.