Fidji Simo Leaves OpenAI: "I Build the Future While Living with an Incurable Illness"
In recent hours, Fidji Simo announced that she will leave her full-time role at OpenAI, where she effectively held the position as the second-in-command to Sam Altman, transitioning to a part-time advisory role. The reason is health-related: a chronic neuroimmune disease she has lived with for seven years, which had severely exacerbated three months ago, forcing her to take medical leave that turned out to be longer and more complex than expected.
Simo was considered the most likely candidate to take on even greater responsibilities once OpenAI went public, and her definitive exit leaves Altman searching for a successor just as the company looks towards a potential IPO, creating a significant gap in the executive frontline.
Today, I shared with the OpenAI team that I have decided to leave my full-time role at OpenAI and transition to being a part-time advisor. Three months ago, I had to go on medical leave after a severe exacerbation of a chronic illness I’ve lived with for seven years. During that — Fidji Simo (@fidjissimo) July 9, 2026
The manager joined OpenAI in May 2025 as CEO of Applications, a newly created role reporting directly to Altman that consolidated business and product operations. With that appointment, COO Brad Lightcap, CFO Sarah Friar, and CPO Kevin Weil began reporting to her, while Altman stepped back to focus on research, computing power, and security. Before OpenAI, of which she was a board member since 2024, Simo had led Instacart to its 2023 IPO, and previously spent over a decade at Meta, where she also directed the Facebook app.
A Chain of Executive Exits
The leave, announced in April due to the relapse of her neuroimmune condition, had triggered months of turnover in the frontline. The same memo indicated that Lightcap was moving to a new role focused on "special projects" and that CMO Kate Rouch was leaving the company. Since then, Weil has also left OpenAI.
During Simo's absence, President Greg Brockman had taken charge of the product; in mid-May, a reorganization officially assigned him product strategy and scaling growth. In an internal memo, Brockman indicated the goal of converging products onto a single agentic platform, merging ChatGPT and Codex into a unified experience.
A Slim Executive Team for an $852 Billion Valuation
From the outside, the lineup of executives appears reduced for a company recently valued at $852 billion. Aside from Altman, Lightcap, Friar, and Brockman, the bench includes Denise Dresser, who arrived in December as chief revenue officer with responsibility for global revenues; she may take on a broader role, leveraging her past as CEO of Slack and her fourteen years at Salesforce.
Simo had focused primarily on growing the consumer-facing business. However, the momentum of ChatGPT slowed toward the end of last year, missing internal revenue targets and prompting the company to place more emphasis on code development tools, an area where it currently lags behind Anthropic.
I am really sad about this and very grateful for all Fidji has done for OpenAI, and even grateful for her friendship and who she is as a person. We all wish her the best for a speedy recovery. This sucks. — Sam Altman (@sama) July 9, 2026
"Three months ago, I had to go on medical leave after a severe exacerbation of a chronic illness I've lived with for seven years," Simo wrote. "It has been a destabilizing experience to spend days contributing to building the future while at the same time facing a debilitating illness that still has no cure."
Altman's reaction came on X: "I am really saddened and very grateful for everything Fidji has done for OpenAI, grateful also for her friendship and for the person she is. We all wish her a speedy recovery. This is hard."