The National Science Foundation (NSF) has put a cork in its grantmaking pipeline after billionaire Elon Musk’s Department of Government Efficiency (DOGE) set up shop at the agency this week.

Effective today, sources tell Science, NSF’s division of grants and awards is returning all grant proposals previously approved for funding and awaiting final signoff to the program officers who oversaw the initial review. In the meantime, according to those sources, NSF will not make any new awards.

The NSF staffers, each of whom oversees a portfolio of grants in their field of expertise, have been asked to determine whether the project can be “mitigated” to avoid running afoul of any presidential directive. Those executive orders prohibit federal agencies from funding research on a range of topics deemed to be discriminatory or at odds with the priorities of President Donald Trump’s administration, including research on fostering diversity in the scientific workforce and combating climate change.

“There is a lot of confusion among the staff,” says one program officer who requested anonymity because they are not authorized to speak for the $9 billion agency. In 2023, NSF reviewed 38,340 competitive proposals and made 11,056 awards.

Shortly after Trump took office, NSF began to vet pending proposals for key words that might invoke the wrath of the new administration. NSF has declined to discuss the fate of research that raised a red flag. But it’s possible the agency had already begun to rework some proposals on the cusp of winning approval before a trio of DOGE workers showed up at the agency’s Alexandria, Virginia, headquarters on Monday.

One NSF-funded researcher who also requested anonymity confirmed today that their pending grant proposal is undergoing what they were told is a “secondary review” after it received a green light from both the program officer and their boss.

NSF declined a request for comment from Science, including how many grants are affected, how the review process would work, and how long it would take.

More: https://www.science.org/content/article/nsf-halts-grant-awards-while-staff-do-second-review