The IUCN coral specialist group and more than 60 experts reassessed 892 reef-building coral species, with enough data to classify 774. Of those, 340, or 44%, fall into Vulnerable, Endangered or Critically Endangered categories: 33 Critically Endangered, 251 Endangered and 56 Vulnerable. Climate-related heat stress determines the final category for 93% of high-risk species. Half of assessed Atlantic species are threatened, compared with 43% in the Indo-Pacific. The coral Red List Index fell from 0.96 before 1998 to 0.89 in 2008 and 0.74 in 2024. The authors warn that data ending in 2020 do not fully capture the 2023-2025 global bleaching event or the 2026-2027 super El Niño, so present risk may be higher; estimated declines also use coral-cover trends as a proxy and need more direct observation.