https://x.com/rookisaacman/status/1928995338729435432
As of now, President Trump has not announced a replacement for Jared Isaacman as NASA Administrator. The White House has stated that a new nominee will be announced soon, emphasizing the need for someone aligned with the "America First in Space" agenda .
Matthew P. Anderson has been previously nominated as deputy administrator. Janet Petro is currently acting as NASA administrator, and Jim Bridenstine was NASA Administrator during Trump's first term.
This answer will resolve to a named person. 'Other' will only win if there is no person confirmed by the expiration date.
Steven L. Kwast, a retired Air Force lieutenant general, was named as the likely new nominee by two sources according to reporter Eric Berger. https://arstechnica.com/space/2025/05/trump-pulls-isaacman-nomination-for-space-source-nasa-is-fed/