OpenAI's Mira Murati steps back to part-time adviser role

Fidji Simo stepped back from OpenAI’s full-time leadership ranks and moved into a part-time advisory role after what she described as a severe flare of a chronic illness she has lived with for seven years. The change strips one of Sam Altman’s most important deputies of day-to-day authority just as OpenAI continues to expand ChatGPT and other applications.

Simo joined OpenAI in May 2025 to lead the company’s applications business, with the company saying she would report directly to Altman as CEO of Applications and help scale its business and operations. By March 2026, her title had grown to CEO of AGI deployment and applications, underscoring how central she had become to OpenAI’s product and commercial strategy.

Her health forced a pause in April 2026, when OpenAI said she was taking several weeks of medical leave because of a worsening neuroimmune condition. Simo later identified the illness as postural orthostatic tachycardia syndrome, or POTS. On July 9, she said she was stepping down from full-time work and would serve the company as a part-time adviser instead, saying recovery would take longer and be more complex than she had expected.

The leadership shift also reorders who is handling OpenAI’s product machinery. During Simo’s absence, OpenAI President Greg Brockman took over product responsibilities, giving him more direct control over the company’s consumer-facing and application side of the business. That handoff matters because OpenAI’s applications arm sits at the center of its push to turn ChatGPT into a broader platform for paid services and enterprise use.

Simo’s path at OpenAI also reflects how quickly the company has reshaped its upper ranks. She joined OpenAI’s board in March 2024, after Altman returned as chief executive, before taking on a full-time operating role the following year. Her move to adviser status comes as OpenAI keeps scaling its products and is widely viewed as preparing for a possible public listing, making the composition of its top leadership newly important to investors, employees and rivals alike.