In 2013, following the recommendations of an internal working group, the NIH announced it was retiring almost all of the government's hundreds of research chimps, but keeping a colony of 50 "reserve" animals in cases of emergency.
Since then, the NIH says it has received only one application to use the chimpanzees. It was later withdrawn.
"We find no evidence that there is a need to continue to do research of an invasive sort on chimpanzees, not now and not going into the future," NIH Director Francis Collins told reporters on Wednesday, calling the decision "inescapable."
In accordance with U.S. law, the animals will be moved to a federally accredited sanctuary. As Chimp Haven is currently the only such facility, it's unclear how long the move will take.
To help Chimp Haven give these animals the retirement they deserve, click here. Or click here to learn more about the HSUS' fight to end primate testing once and for all.