Musk v. OpenAI Timeline: The Lawsuit, Trial and 2026 Verdict
Musk v. OpenAI timeline: 51 dated events from the 2015 nonprofit launch to the May 2026 jury verdict and the appeal, with Musk’s $38 million in donations, Microsoft’s billions, every key filing and ruling, the trial witnesses, a map and a source for each event.
OpenAI launches as a nonprofit with $1 billion in pledges
OpenAI announces itself as a nonprofit artificial intelligence research company. Its backers, among them Elon Musk, Sam Altman, Reid Hoffman and Peter Thiel, pledge a combined $1 billion. Musk and Altman are named co-chairs. Greg Brockman and Ilya Sutskever join as founders. The nonprofit form is the fact the later lawsuit turns on. Musk would argue that his money came with a promise that OpenAI would stay a charity working for the public.
2016 (approx.): Musk starts paying OpenAI $5 million a quarter
Through 2016 and 2017 Musk sends OpenAI $5 million each quarter, much of it through the fiscal sponsor YC.org and donor advised funds, the court later found. He also covers about $12.7 million of office rent through September 2020. The court put his total giving at about $38 million. That figure, not the $1 billion pledge of 2015, is the money the 2026 trial argued about.
August 2016: Musk and Altman weigh Amazon against Microsoft
In emails shown at the 2026 trial, Musk and Altman discuss whether OpenAI should run on Amazon or Microsoft servers. Musk writes that he slightly prefers Microsoft. Brockman later testified that Microsoft played no role in the founding. The emails mattered because Musk’s case blamed Microsoft for pulling OpenAI away from its charity. They show Musk was part of the first conversation about Microsoft.
2017 (approx.): Musk asks for majority equity and the CEO title
As the founders discuss a for-profit structure, Musk asks for majority equity and the chief executive title, according to OpenAI and the trial record. Altman, Brockman and Sutskever refuse. Musk testified that he did not oppose a small for-profit arm “as long as the tail didn’t wag the dog.” OpenAI told jurors that 2017 was the year Musk first had reason to sue.
OpenAI bot beats a Dota 2 professional at The International
An OpenAI bot beats a professional player at one-on-one Dota 2 during The International tournament in Seattle. At the 2026 trial the win was described as a turning point that led to the for-profit discussions. Sutskever told jurors that the need for huge amounts of computing power, and the money to buy it, drove the talks about a for-profit arm.
November 2017: Brockman writes private notes about a for-profit
Greg Brockman writes notes in his personal journal about wanting a for-profit structure. In January 2026 Judge Yvonne Gonzalez Rogers wrote that the notes suggested the nonprofit assurances given to Musk might be dishonest and could be read as showing intent to deceive. Brockman was ordered to hand over the diary. One entry read in the case: “When will I ever have a chance to be free and truly own my destiny?”
January 2018: Musk proposes folding OpenAI into Tesla
Musk proposes merging OpenAI into Tesla. In an email OpenAI published in 2024 he writes that “Tesla is the only path that could even hope to hold a candle to Google.” His co-founders reject the plan. Altman testified in 2026 that Musk “wanted total control” of any for-profit entity, and called Musk’s answer about passing control to his children a “hair-raising moment.” A month after the Tesla proposal Musk was gone.
Musk leaves the OpenAI board
OpenAI announces that Musk will leave its board, citing a possible conflict with Tesla’s own AI work for self-driving cars. Later reporting and the court record place the cause in the fight over control. Musk agrees to keep donating and advising, and gives about $10 million more over the next three years. Sutskever testified that Musk said at the time that OpenAI had a “0 percent chance of success.”
December 2018: Musk emails that OpenAI needs billions a year
In an email that OpenAI published in March 2024, Musk writes: “Even raising several hundred million won’t be enough. This needs billions per year immediately or forget it.” OpenAI used the email to argue that Musk accepted the need for outside capital long before he sued. Musk’s case was that needing money never licensed handing the charity’s assets to investors.
OpenAI creates the capped-profit company OpenAI LP
OpenAI announces OpenAI LP, a “capped-profit” company under the nonprofit board. According to the court’s summary of the record, the profit cap sat above $250 billion and substantially all of the nonprofit’s intellectual property and employees moved into the new company. The record shows Musk was not told those specifics. OpenAI argued the public announcement alone should have put him on notice.
Microsoft invests $1 billion in OpenAI
Microsoft announces a $1 billion investment and a multiyear partnership to build supercomputing capacity on its Azure cloud for OpenAI. Musk testified in 2026 that he saw “no basis” to sue at the time. The partnership later became the center of his claim that Microsoft knowingly helped OpenAI’s leaders break their promises, a claim that survived until the jury ruled.
Musk makes his last payment to OpenAI
Musk’s final payment to OpenAI arrives, according to the court. It closes a run of giving the court totals at about $38 million, including roughly $12.7 million in rent for OpenAI’s offices in San Francisco. His lawyers later pointed to payments continuing well after 2019 as proof that he still trusted the assurances Altman and Brockman had given him.
Microsoft gets an exclusive license to GPT-3
Microsoft secures an exclusive license to OpenAI’s GPT-3 language model. At trial OpenAI cited the deal as one more public fact that should have told Musk where the company was heading. Musk testified that Altman had reassured him the company was staying a nonprofit, and that he saw no reason to sue in 2020.
Musk posts that OpenAI is “essentially captured by Microsoft”
Days after the GPT-3 license, Musk writes on Twitter that OpenAI is “essentially captured by Microsoft.” Six years later the post worked against him. OpenAI’s lawyers used statements like it to show jurors that Musk knew of the conduct he sued over years before the deadlines to sue ran out.
2021: Microsoft invests a further $2 billion
Microsoft adds $2 billion, according to the court’s account of the record. Its investments reach $1 billion in 2019, $2 billion in 2021, $10 billion in January 2023 and $750 million in late 2024. The court later held that a 2018 email from Microsoft’s chief technology officer and notes from an October 2020 meeting were enough to put the question of what Microsoft knew before a jury.
OpenAI releases ChatGPT
OpenAI releases ChatGPT to the public as a free research preview. Musk testified that 2022 was when he discovered the nonprofit mission had been abandoned. As Microsoft prepared a $10 billion investment at a valuation of about $20 billion, he texted Altman: “This is a bait and switch.” Microsoft announced the deal two months after the ChatGPT launch.
Microsoft confirms a multibillion dollar investment in OpenAI
Microsoft confirms a “multiyear, multibillion dollar” investment in OpenAI, which the court record later put at $10 billion. Musk’s lawyer Steven Molo told jurors in closing that “the 2023 deal was different.” His timing argument rested on it: if the harm began in 2023, a suit filed in 2024 was on time. The jury did not accept that.
Altman asks Shivon Zilis how to handle Musk’s public attacks
Altman asks Shivon Zilis, a former OpenAI board member and the mother of several of Musk’s children, for advice about praising Musk publicly, according to case files disclosed in 2025. The same month Altman emails Musk that he is “tremendously thankful” for his help and that the public attacks hurt. Musk replies: “I hear you and it is certainly not my intention to be hurtful, for which I apologize, but the fate of civilization is at stake.”
Musk founds xAI
Musk launches xAI, his own artificial intelligence company. By May 2024 it had raised $6 billion at a $24 billion valuation. OpenAI argued throughout the case that Musk sued to undercut its growth and help xAI. xAI later backed Musk’s 2025 bid for OpenAI’s nonprofit and sued OpenAI itself over trade secrets.
OpenAI board fires Sam Altman, then takes him back
OpenAI’s board removes Altman as chief executive, saying he was not consistently candid with it. Brockman quits the same day. Microsoft offers both men jobs, and most of OpenAI’s staff threaten to leave. Five days later an agreement returns Altman as CEO with a new board. Sutskever, who voted to remove him, told jurors in 2026 that he regretted voting to bring him back.
Musk sues OpenAI and Altman in San Francisco Superior Court
Musk files suit in San Francisco Superior Court against Altman, Brockman and OpenAI, accusing them of abandoning the founding mission of building AI for the benefit of humanity rather than for profit. He asks the court to force OpenAI to make its research and technology public and to stop it using assets such as GPT-4 for the financial benefit of Microsoft and others.
OpenAI publishes Musk’s old emails
OpenAI answers the suit in a blog post that publishes Musk’s emails from 2017 and 2018, including his call for billions a year and his argument that Tesla was the only realistic source of that money. “We’re sad that it’s come to this,” the post says. The emails became the core of OpenAI’s defense: Musk knew of the for-profit plans, and backed some of them, years before he sued.
Musk withdraws the state court suit
Musk’s lawyers ask the San Francisco court to dismiss the case, one day before a judge was due to hear OpenAI’s motion to throw it out. They give no reason. The dismissal is without prejudice, which leaves Musk free to bring the claims again. He refiled in federal court eight weeks later.
Musk refiles in federal court, case 4:24-cv-04722
Musk files a new and broader suit in the US District Court for the Northern District of California. The case, Musk v. Altman, number 4:24-cv-04722, goes to Judge Yvonne Gonzalez Rogers in Oakland. The federal complaint keeps the broken-promise theory and adds new legal claims. Every later ruling, from the injunction fight to the verdict, came from this courtroom.
Amended complaint adds Microsoft and antitrust claims
Musk’s amended complaint names Microsoft as a defendant, along with former OpenAI board member Reid Hoffman and Microsoft executive Dee Templeton, and adds antitrust claims. It runs to 26 claims in all. Later that month Musk asks the court for a preliminary injunction to stop OpenAI converting into a for-profit company. Of the 26 claims, two reached the jury in 2026.
OpenAI says Musk wanted a for-profit he would control
OpenAI publishes a second set of messages from 2017. It says Musk agreed the nonprofit had to become a for-profit to pursue its mission, and proposed a board structure in which he “would unequivocally have initial control of the company.” OpenAI says it refused those terms. Musk’s position was that wanting control of a for-profit arm was different from agreeing to strip the charity.
Judge questions Musk’s harm claim at the first hearing
At a hearing in Oakland on the injunction request, Judge Gonzalez Rogers questions Musk’s claim that OpenAI’s conversion would cause him irreparable financial harm, calling it a stretch. She describes the dispute as “billionaires versus billionaires.” A ruling on the injunction followed four weeks later.
Musk-led group bids $97.4 billion for OpenAI’s nonprofit
A consortium led by Musk and backed by xAI offers $97.4 billion for the nonprofit that controls OpenAI. Altman replies on X: “No thank you but we will buy twitter for $9.74 billion if you want.” OpenAI later listed the offer in its counterclaims as “a sham bid for OpenAI’s assets,” part of what it called a years-long harassment campaign.
Judge denies Musk’s bid to block the for-profit conversion
Judge Gonzalez Rogers denies Musk’s motion for a preliminary injunction that would have stopped OpenAI converting into a public benefit corporation before trial. She offers to expedite a trial on the conversion claim to fall 2025, with other claims stayed, and notes the full case would otherwise not be ready for trial until 2027 or 2028. The trial finally opened in April 2026.
OpenAI countersues Musk for harassment
OpenAI files counterclaims accusing Musk of a years-long harassment campaign of press statements, social media posts, legal claims and a sham bid for its assets, all meant to slow the company down. The counterclaims sat outside the 2026 jury trial. The court’s January 2026 ruling left them, with Musk’s antitrust claims, for a later phase of the case.
Twelve former OpenAI employees file a brief backing Musk
Twelve former OpenAI employees file an amicus brief in Musk’s case, supported by Harvard law professor Lawrence Lessig. They argue that taking control away from the nonprofit would betray the mission they joined for. The brief calls Altman a person of “low integrity” and says he misled employees about non-disparagement agreements. Altman and OpenAI denied wrongdoing throughout the case.
Judge trims the suit but keeps the fraud claims alive
Judge Gonzalez Rogers dismisses Musk’s false advertising and breach of fiduciary duty claims against OpenAI, and lets his fraud and unjust enrichment claims go forward. The ruling keeps Altman, Brockman and the OpenAI entities in the case. Unjust enrichment was one of the two claims that finally reached the jury a year later.
OpenAI says its nonprofit will keep control
OpenAI drops its plan to separate its business from the nonprofit board. Its for-profit arm will become a public benefit corporation that the nonprofit still controls. The same day Musk’s lawyer Marc Toberoff says the lawsuit will continue. The change removed one of Musk’s requests but not his claim that the charity’s assets had already been diverted.
Judge refuses to dismiss OpenAI’s harassment counterclaims
Judge Gonzalez Rogers denies Musk’s motion to dismiss OpenAI’s counterclaims, which accuse him of a years-long harassment campaign that included the $97.4 billion offer. Both sides now had live claims against each other. The counterclaims were later left for a second phase, after the jury trial on Musk’s claims.
xAI sues OpenAI over trade secrets
Musk’s xAI opens a second front, suing OpenAI in federal court in San Francisco and alleging it hired away xAI staff to obtain its trade secrets. OpenAI denies the claims. The case went to US District Judge Rita Lin. She dismissed a first version in February 2026 and the amended case in June 2026.
OpenAI completes its recapitalization into a public benefit corporation
OpenAI restructures. Its business becomes OpenAI Group PBC, a public benefit corporation. The nonprofit, now the OpenAI Foundation, keeps control and a stake of about 26 percent, valued at roughly $130 billion. Microsoft holds about 27 percent. Musk later asked the court to unwind the change and remove Altman and Brockman. The jury never reached that request.
Judge sends Musk’s claims against OpenAI to a jury
Judge Gonzalez Rogers denies OpenAI’s motion for summary judgment on all four claims against it: breach of charitable trust, constructive fraud, fraud and unjust enrichment. She cites “ample evidence in the record,” including Brockman’s 2017 notes. Against Microsoft she grants judgment on two claims but keeps the claim that it aided and abetted a breach of fiduciary duty. When Musk learned of the conduct, she rules, is a disputed fact for the jury.
Musk’s expert puts damages at $79 billion to $134 billion
In a court filing, Musk’s lawyers set out a damages claim of $79 billion to $134 billion against OpenAI and Microsoft, calculated by financial economist C. Paul Wazzan of Berkeley Research Group. OpenAI answers with a blog post titled “The truth Elon left out,” publishing internal emails and call notes from 2017. A day earlier it had warned investors that Musk would make “deliberately outlandish, attention-grabbing claims” before trial.
Pretrial hearing: ketamine questions barred, Burning Man allowed
At a pretrial hearing the judge questions the method behind the $134 billion damages figure but does not exclude Musk’s expert. She bars questions about Musk’s alleged ketamine use, allows limited questions about his attendance at the 2017 Burning Man festival and signals she will likely reject punitive damages. Jury selection was then six weeks away.
Musk asks that any damages go to OpenAI’s charity
Three weeks before trial, Musk amends his complaint to ask that any damages be paid to OpenAI’s nonprofit rather than to him, and that Altman be removed from the board. The change recast the case as a suit to restore a charity. Musk no longer sought personal damages when the jury was seated.
Musk drops his fraud claims days before trial
The judge grants Musk’s request to narrow the case. The fraud claims fall away, and two of the 26 claims in his November 2024 complaint go to trial: unjust enrichment and breach of charitable trust. Musk still seeks up to $134 billion for OpenAI’s charitable arm, the restoration of its nonprofit status and the removal of Altman and Brockman from their roles.
Jury selection: nine jurors seated for an advisory verdict
Nine jurors from the Bay Area are seated in Oakland. Their verdict will be advisory: Judge Gonzalez Rogers, who chose that format before trial, will make the final decision. Musk does not attend and posts on X that the defendants “stole a charity. Full stop.” OpenAI attorney William Savitt tells reporters: “It’s a good jury, and they’re going to hear the facts, and we’re going to get a verdict.”
Musk testifies over three days
After opening statements Musk takes the stand, questioned by OpenAI attorney William Savitt and his own lawyer Steven Molo. He describes three phases in his view of OpenAI, the last summed up as “I’m sure they’re looting the nonprofit.” The judge scolds him over posts calling the defendants “Scam Altman” and “Greg Stockman” and threatens a gag order. Musk, Altman and Brockman agree to limit posts about the case.
Satya Nadella testifies for Microsoft
Microsoft chief executive Satya Nadella testifies that Musk never raised concerns with him about Microsoft’s investment in OpenAI, and that he was never given clarity on why the board fired Altman in 2023. Two days later Microsoft’s chief technology officer and its head of corporate development tell jurors that the company’s due diligence found no agreement with Musk about a for-profit subsidiary.
Ilya Sutskever testifies about the 2023 ouster
OpenAI co-founder Ilya Sutskever tells jurors he spent months gathering evidence of what he called Altman’s pattern of deception and poor management before the 2023 board vote, and that he regretted later voting to bring him back. He also explains that the need for vast computing power drove the for-profit talks, and compares AI in 2018 with AI today as the difference between “an ant and a cat.”
Sam Altman testifies: “I believe so”
Altman testifies that Musk wanted complete control of OpenAI and pushed to make it part of Tesla before he left. Musk’s lead counsel Steven Molo opens the cross-examination with “Are you completely trustworthy?” Altman answers: “I believe so.” He calls the 2023 board episode an “incredible betrayal” and says of the charge that OpenAI stole a charity: “It feels difficult to even wrap my head around that framing.”
Last day of testimony: OpenAI’s experts and a safety trophy
OpenAI calls its experts. Tax lawyer Daniel Hemel says 92 percent of the 100 largest US charities he examined have for-profit subsidiaries. Forensic accountant Louis Dudney testifies that all of Musk’s donations went to the nonprofit’s mission. Researcher Joshua Achiam recalls a 2018 all-hands meeting where Musk called him a “jackass” for calling an AGI race unsafe, and the trophy colleagues gave him: “Never stop being a jackass for safety.”
Closing arguments: 150 to 200 answers of “I don’t recall”
Molo tells jurors Altman “can’t be trusted.” The judge interrupts him over a statement about damages and orders a retraction. Savitt counts 150 to 200 answers of “I don’t recall” or “I don’t remember,” nearly all from Musk’s side, and says Musk’s gifts came with conditions that left OpenAI “tied in knots.” Musk is absent, in China with President Trump. Deliberations are set for Monday.
Verdict: jury finds Musk sued too late
After a three-week trial the nine jurors take less than two hours to find, unanimously, that Musk’s claims are barred by the statutes of limitations: he had reason to believe he was being misled before 2021. Judge Gonzalez Rogers adopts the advisory verdict at once, saying “there’s a substantial amount of evidence to support the jury’s finding,” and dismisses the claims, including the one against Microsoft. The jury never decided whether Musk was in fact misled.
Musk vows to appeal a “calendar technicality”
Musk writes on X that the judge and jury “never actually ruled on the merits of the case, just on a calendar technicality,” and says he will take the case to the Ninth Circuit Court of Appeals in San Francisco. His lawyer Molo compares the loss to the Siege of Charleston and Bunker Hill. Savitt says jurors found the suit an “after-the-fact contrivance.” Microsoft says it remains committed to its work with OpenAI.
Judge throws out xAI’s trade secrets case with prejudice
US District Judge Rita Lin dismisses xAI’s trade secret suit against OpenAI with prejudice, saying further amendment would be futile. xAI cannot bring the same claims again. It is Musk’s second courtroom loss to OpenAI in four weeks. His lawyers have said they will appeal the May verdict. No ruling on that appeal had been reported when this timeline was published in November 2026.