The last remaining research chimpanzees in the U.S. government are headed for a retirement home.

The National Institutes of Health shut down most research on chimps in 2013, but kept 50 of the apes in case of a public health emergency. On Wednesday, NIH announced those last chimps would sent to a sanctuary to live out their lives in the midst of nature. Another 82 chimpanzees the NIH supports at other research laboratories will also be headed into retirement.

About 300 government chimpanzees have already been sent to Chimp Haven in Louisiana. It has a waiting list and animal advocacy groups are working with the NIH to find new homes for the newly retired research apes.

The federal government relied on chimps for research during the early days of the space program and for decades to test new drugs because the apes are genetically and biologically similar to humans. The need to use them for any kind of research has become increasingly rare in recent years.

Earlier this year, the Fish and Wildlife Service gave research chimpanzees the same protections it provides endangered species. The move banned all invasive research on chimps in the U.S.

"It's time to say we've reached the point in the U.S. where invasive research on chimpanzees is no longer something that makes sense," said Dr. Francis Collins, Director of NIH, told ABC News.

(Photo: frank wouters, CC)