Musk-OpenAI lawsuit set for April 28 court start

A legal dispute between Elon Musk and OpenAI is scheduled to move into open court on Monday, April 28, 2026, placing the organization’s mission and corporate structure at the center of a closely watched trial. The lawsuit names OpenAI CEO Sam Altman and lists Microsoft as a co-defendant, according to the complaint.

The proceedings are expected to attract broad attention because they involve prominent technology figures and a sector described as central to global competition. The court will focus on the legal claims and requested remedies, but the case is also being monitored by investors and corporate partners given the companies involved.

Claims focus on OpenAI’s mission and structure

Musk, described in the source material as a co-founder and early funder of OpenAI, is suing over what he argues was a shift away from the organization’s original purpose. He alleges OpenAI began as a non-profit intended to develop open-source artificial intelligence for public benefit, but later moved toward a for-profit approach.

In the complaint, Musk contends that the change altered obligations he says OpenAI owed as a charitable entity and conflicted with the intent behind his early backing. The lawsuit frames the dispute as a challenge to how OpenAI’s governance and mission evolved over time.

Corporate milestones cited in the complaint

The lawsuit highlights two corporate steps as central to Musk’s claims. It says OpenAI created a for-profit subsidiary in 2019 and later converted to a public benefit corporation in 2025.

Musk argues those moves amount to a breach of charitable trust and unjust enrichment. He also maintains that his initial contributions—about $44 million—were provided with the expectation they would support a non-profit organization.

Microsoft named as co-defendant as IPO questions linger

Microsoft, identified as a major investor in OpenAI, is accused in the case of aiding and abetting the alleged breach. The dispute is described as potentially consequential for OpenAI’s future, including reported plans for an initial public offering (IPO).

While the court’s task is to evaluate the claims presented, the case’s path could intersect with issues relevant to capital raising and corporate partnerships. With OpenAI and Microsoft both implicated, the proceedings are also being watched for potential effects on relationships among major AI developers and investors across global markets.

Jury selection expanded; judge to decide remedies

The trial is set to open with an unusually large jury selection process. The pool will be three times larger than what is typical in a civil case, reflecting the prominence of the parties and the significance of the technology at issue.

The jury is expected to provide an advisory view on liability, but Judge Yvonne Gonzalez Rogers will make the final decision on remedies. Several outcomes remain unclear, including what remedies could be ordered if Musk prevails, and the source material notes uncertainty around how the result could affect OpenAI’s leadership and competitive dynamics across the artificial intelligence sector.