Fourteen federal research agencies reported a large net outflow of Ph.D.-level STEM and health staff in 2025, with hires trailing departures by about 11 to 1 and a net loss of roughly 4,224 Ph.D.s, Science’s analysis shows. The National Institutes of Health and the National Science Foundation recorded steep declines amid retirements, resignations and reduced rotator programs. Science’s review of Office of Personnel Management data found that voluntary departures—retirements and quits—drove the shrinkage more than formal reductions in force. Observers tied the trend to policy uncertainty, proposed budget cuts, and a shrinking rotator pipeline that historically channels academic talent into government research. The shortfall raises alarms for university researchers who collaborate with federal labs and rely on agency grants. Reduced in-house expertise could slow peer review, program operations, and federally funded research initiatives, while universities compete to retain faculty who previously rotated into agency roles.