The National Science Foundation placed holds on future awards for Duke, Harvard, Princeton, and Yale, limiting new grant activity after April 9, according to internal agency documents obtained by Nature. The freeze does not halt existing award spending, but it sharply reduced new awards and paused proposals from researchers at the four institutions. Nature reports that the four universities received a combined total of 218 new NSF grants in 2024, but in the current fiscal year they had only 13 new grants. Since the hold began, none of the new grants went to scientists at Duke or Harvard, and the NSF Office of Award Management paused 33 proposals from the four schools. The agency’s Office of Award Management typically takes about 10 days to finalize proposals, but the documents show average delays of 91 days for the affected researchers. NSF did not comment on why the institutions were singled out. For campus research leaders, the immediate risk is timing: program delays can affect hiring, procurement, and downstream research timelines while the reasons for the holds remain unclear.