Species reintroductions may mitigate the effects of severe amphibian declines, but chytridiomycosis—the often-deadly amphibian disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd)—can hinder these efforts. Exposing amphibians to the pathogen ex-situ may improve disease outcomes post-release. We experimentally inoculated the federally threatened California red-legged frog (Rana draytonii) ex situ, cleared Bd infections, then released them to the wild for monitoring in an area where Bd is present. Ex situ, previously-exposed frogs had lower Bd...