Conservation prioritisation emphasises currently threatened species, but there are strong arguments for complementary, more proactive approaches based on forecasting future extinction risk for unthreatened species. Forecasting methods vary in the timescale of extinction risk estimation and include established methods such as Population Viability Analysis (PVA) and Early Warning Systems, and emerging ‘Over-the-Horizon’ (OTH) methods. We develop a framework that integrates extinction risk assessment across timescales and outlines tradeoffs between shorter- and longer-term extinction prevention goals. This framework facilitates use of extinction risk forecasting in decision-theoretic conservation prioritisation that explicitly considers alternative time horizons for extinction prevention. Considering extinction risk on extended timescales offers a future-proof approach to conservation planning that may prevent more extinctions than focusing exclusively on currently threatened species.