type: timeline_event
HHS Deputy Secretary Jim O'Neill and General Counsel Mike Stuart leave their positions as part of a leadership shakeup orchestrated by Secretary Robert F. Kennedy Jr. ahead of the 2026 midterm elections. O'Neill, who served as Kennedy's top aide and Acting Director of the Centers for Disease Control and Prevention, was a controversial figure who amplified anti-vaccine messaging, promoted concerns about Medicaid fraud, and championed U.S. departure from the World Health Organization. Within the administration, O'Neill was viewed as a shaky public communicator who struggled to find his fit within the department. O'Neill's statutorily temporary acting CDC director appointment was set to expire March 27, 2026—210 days from his initial appointment. He updates his X account bio to "formerly @hhsgov" confirming his departure.
Stuart, HHS's top lawyer as General Counsel, also exits as part of the reorganization. Both officials will be offered new roles within the Trump administration, though their placement—whether within HHS or at other agencies—remains unclear at the time of announcement. The staff shuffle elevates Medicare director Chris Klomp to effectively function as chief of staff under Kennedy, overseeing all departmental operations while continuing to serve as Medicare director. The changes also promote FDA deputy commissioners Kyle Diamantas and Grace Graham to senior counselors at the agency. No immediate successor for the CDC acting director position is announced.
The departures coincide with Kennedy's public emphasis on administration priorities including cleaning up the food supply and lowering drug prices, occurring alongside broader uncertainties in the nation's health system including Medicaid cuts passed by Congress and expiring Affordable Care Act subsidies threatening millions of Americans' insurance coverage. The leadership shakeup follows revelations that Kennedy violated multiple promises made during his confirmation hearings to secure Senate approval. Despite pledging not to cut vaccine funding or change official vaccine recommendations, Kennedy pulled back $11 billion in COVID-era grants funding local health department vaccination programs and ordered cancellation of $500 million in mRNA vaccine research in August 2025. Kennedy also failed to honor his commitment to Republican Sen. Bill Cassidy to testify before the Senate Health Committee quarterly—five months after Cassidy's September 18, 2025 invitation, no hearing has occurred and no date is set.
The timing of the staff overhaul positions Kennedy to install loyalists focused on his "Make America Healthy Again" agenda as the administration faces increasing criticism over dramatic policy reversals, scientific integrity concerns, and systematic dismantling of public health infrastructure. O'Neill's departure removes the official who signed the January 5, 2026 decision memorandum slashing CDC childhood vaccine recommendations from 17 to 11 diseases without consulting the Advisory Committee on Immunization Practices or soliciting public comment—a move that drew condemnation from medical professionals and raised legal questions about Administrative Procedure Act compliance.