The global rise in noncommunicable diseases (NCDs) and the rapid aging of populations have placed growing pressure on healthcare systems worldwide, underscoring the urgent need to shift from reactive to preventive models of care. This chapter explores the strategic integration of preventive healthcare into public policy as a pathway to achieving lifelong well-being and health system sustainability. Preventive healthcare, encompassing primary, secondary, and tertiary levels of intervention, serves as a critical tool to reduce disease incidence, detect conditions early, and manage health proactively across the lifespanLifespans. The conceptual foundation of the chapter is rooted in established behavioral and public health theories, including the Health Belief Model (HBM) and Social-Ecological Model (SEM), which guide the development of population-level prevention strategies. Case studies from Finland, Canada, Japan, and other countries illustrate how preventive approaches can be scaled through thoughtful legislation, cross-sector collaboration, and community engagement. The chapter emphasizes the need for intersectoral alignment between health, education, environmental, and social services, recognizing that long-term health outcomes are shaped by a broad range of social determinants. Practical implementation strategies are examined in detail, including health educationHealth education, digital technologies such as mobile health (mHealth), electronic health (eHealth) platforms, telemedicine, and artificial intelligence (AI) for risk prediction and personalized intervention. The integration of prevention into primary carePrimary care models, supported by financial incentives and equitable accessEquitable access, is presented as essential to operationalizing change at the system level. Barriers to effective implementation are critically analyzed, including inconsistent political support, underfunding, behavioral resistance, and structural inequities. The chapter concludes with clear policy and practice recommendations, alongside future research priorities in areas such as digital prevention tools, emerging public health challenges, and longevity scienceLongevity science. By embedding prevention into the core of health governance and service delivery, countries can build more resilient, equitable, and forward-looking systems that promote not just longer life, but better life.