Not long after President Donald Trump started his second term, many scientists funded by the U.S. National Institutes of Health (NIH) began to be asked by the agency to strip certain words from their grants, sparking cries of research censorship and politicization. Now, their projects are facing an even higher level of scrutiny from the Trump administration. According to documents viewed by Science, all grants approved by NIH for funding are now going through an extra screening at its parent body, the Department of Health and Human Services (HHS). Staffers there who may be political appointees and not necessarily subject matter experts sometimes ask for substantive changes in the research.

Some NIH career employees involved in the grant-review process say the HHS requests are unprecedented and alarming. “The U.S. scientific community and the broader American public should be deeply concerned by the fact that HHS is overriding peer review to require changes to research scope, design, and language,” says Jenna Norton, an NIH program officer who stresses she is speaking in her personal capacity, not on behalf of NIH. (Norton was put on leave last fall after leading protests against Trump administration actions, but has since been reinstated.)

The extra layer of review includes both new proposals that NIH deemed worth funding and ongoing grants awaiting their annual payment. HHS reviewers in several cases have even asked for changes in the work to be conducted near the end of a multiyear grant when a course correction would be impossible, according to NIH staffers who spoke with Science on the condition of anonymity to protect their jobs.