AbstractRestoringgene flowamong fragmented populations is discussed as a potentially powerful management strategy that could reduce inbreeding depression and causegenetic rescue. Yet, examples ofassisted migrationforgenetic rescueremain sparse in conservation, prompting several outspoken calls for its increased use in genetic management of fragmented populations. We set out to evaluate the extent to which this strategy is underused and to determine how many imperiled species would realistically stand to benefit fromgenetic rescue, focusing on federally threatened or endangered vertebrate species in the United States. We developed a “genetic rescue suitability index (GR index)” based on concerns about small population problems relative to risks associated withoutbreeding depressionand surveyed the literature for 222 species. We found that two-thirds of these species were good candidates for consideration ofassisted migrationfor the purpose ofgenetic rescueaccording to our suitability index. Good candidate species spanned all taxonomic groups and geographic regions, though species with more missing data tended to score lower on the suitability index. While we do not recommend a prescriptive interpretation of our GR index, we used it here to establish thatassisted migrationforgenetic rescueis an underused strategy. For example, we found in total, “genetic rescue” was only mentioned in 11 recovery plans and has only been implemented in 3 of the species we surveyed. A potential way forward for implementation of this strategy is incorporatinggenetic rescueas a priority in USFWS recovery documentation. In general, our results suggest that although not appropriate for all imperiled species, many more species stand to benefit from a conservation strategy ofassisted migrationforgenetic rescuethan those for which it has previously been considered or implemented.