The National Institutes of Health (NIH) announced plans to reduce the use of chimpanzees in NIH-funded biomedical research on June 26, 2013. The decision was made in response to recommendations from an NIH working group about how to implement the IOM report Chimpanzees in Biomedical and Behavioral Research: Assessing the Necessity. Going forward, the NIH will retain but not breed up to 50 chimpanzees for future research, and only that research which meets the principles and criteria set forth in the IOM report. The NIH will also establish a panel to review research projects proposing the use of chimpanzees against the IOM’s principles and criteria, subsequent to NIH peer review. In addition, the NIH will wind down projects using NIH-owned or -supported chimpanzees that do not meet the IOM principles and criteria. As a result of these changes, most NIH-owned or -supported chimpanzees will be designated for retirement.