We are entering a historic demographic transition: within decades, one-third of our lives will unfold after age 60, and functional decline typically begins ten to twenty years before disease onset. Yet aging is increasingly malleable: today’s 68-year-olds show the functional profile 62-year-olds showed in earlier cohorts, a measured gain in intrinsic capacity. This gain has not yet translated into a matching compression of morbidity, and the gap between lifespan and healthspan continues to widen. Closing it through geroscience-based prevention is both a scientific opportunity and a public health necessity.This Call to Action synthesizes contributions from 60 experts convened at the Paris Healthy Longevity Summit (May 20, 2026, French National Academy of Medicine, Paris) under the High Patronage of President Emmanuel Macron, organized around one guiding question: how to make healthy longevity accessible to the greatest number of people. Contributions were synthesized into five priority pillars and fifteen actions.Five priority pillars emerged: embedding prevention across the life course; large-scale deployment of the WHO’s ICOPE program; adapting health care professional training; investing in geroscience research and biomarker validation; and changing the cultural image of aging while reorganizing care around healthy longevity. Key recommendations include a healthy longevity check-up from age 50, systematizing ICOPE assessment at every point of contact with the population, a geroscience biomarker-validation consortium, and territorial Healthy Aging Coalitions to reduce socioeconomic gaps in healthy life expectancy.It is addressed to public authorities, health care institutions, research funders, employers, insurers, and civil society: the evidence is converging, and stakeholders are ready to act.