In March 2025, the National Institutes of Health (NIH) announced that it would be terminating $1.8 billion in grant funding unaligned with the agency’s priorities. The proportion of grant funding that was terminated varied substantially across institutes, with 0.5% of grant funds terminated at the National Heart, Lung, and Blood Institute, 2.3% of funds at the National Cancer Institute, and approximately 6% at the Institutes focusing on alcohol, mental health, and infectious disease. The NIH supports a broad array of research programs and funding mechanisms, and these prior analyses provided an important high-level view. However, clinical trials deserve close scrutiny, in that they expose patients to risks and are essential to generating high-quality evidence. In this issue of JAMA Internal Medicine, Patel et al address a key knowledge gap by characterizing NIH terminations of grants that supported ongoing clinical trials. They found that in the first half of 2025, the NIH terminated grants supporting 383 unique clinical trials, affecting 74 311 individuals.
