With hundreds of species on the brink of extinction, conservation practitioners must decide which conservation actions to implement given limited funds. Decision processes that aim to maximize conservation benefit for a given cost should address complementarity of actions across taxonomic groups. To address this need we modified a Priority Threat Management approach to guide resource allocation decisions for the conservation of biodiversity in Maui Nui (the islands of Maui, Moloka‘i, Lāna‘i, and Kahoʻolawe). Through expert elicitation, data were gathered on: (1) key threats to sensitive species; (2) management strategies to address key threats; and (3) expected cost, feasibility, and benefit of management strategies. Elicited data were analyzed to identify strategies that would provide optimal gains in recovery across multiple taxonomic groups given costs and feasibility. Predator control and fencing were identified as cost-efficient actions with the greatest gains in recovery across taxonomic groups, but those actions alone were not effective at recovering many plants and invertebrates. Participants emphasized the importance of investing in research and development of novel techniques to address persistent problems such as avian malaria and invasive pests. Findings from this study will improve the efficient use of existing funds and competitiveness for resources needed to achieve recovery.