With recent medical, technological, and socioeconomic developments, people are living longer. The rising average age of the world's population presents an opportunity to develop health policy that prioritizes functioning as a goal of healthy aging. In February 2024, the National Academies convened a hybrid workshop at the University of Lucerne in Switzerland to host a discussion focused on the World Health Organization's concept of functioning. Speakers paid particular focus to healthy aging and the future of rehabilitation as a health strategy. Experts emphasized that the need for rehabilitation is increasing due to rapid population aging accompanied by a rise in physical and mental health conditions, limitations, and injuries. The associated economic and practical obstacles of optimizing functioning across the life course were also discussed.