The U.S. National Institutes of Health is facing a leadership vacuum with 15 of its 27 institutes currently led by acting directors [1], [2].
This instability at the top of the federal government's primary biomedical research agency threatens the continuity of long-term scientific goals. The lack of permanent leadership may slow the approval of research grants and the implementation of new public health strategies.
The vacancies follow a wave of senior departures that began after President Donald Trump returned to office in January 2025 [3], [5]. This trend has left nearly half of the agency's top roles vacant [3]. While some reports indicate more than half of the institutes and centers lack permanent directors [4], others specify the number of institutes under acting leadership at 15 of 27 [1], [2].
These gaps in leadership are centered at the NIH campus in Bethesda, Maryland [3], [4]. The prolonged vacancy has lasted for several months as of this week, creating an environment where the agency's direction remains in flux.
Observers said the slow pace of permanent appointments has created an opportunity for the political reshaping of the agency [3], [4]. By maintaining acting directors in place, the administration can exercise more direct influence over the NIH's priorities without the immediate need for Senate confirmation of permanent heads.
The NIH continues to struggle to fill these roles as the administration navigates the transition of its scientific leadership.
“15 of the 27 institutes are led by acting directors”
The high volume of acting directors suggests a strategic shift in how the U.S. government manages scientific research. By delaying permanent appointments, the administration maintains flexibility to align the NIH's research agenda with current political priorities, though this risks alienating the career scientific community and disrupting global research partnerships.
