This study investigated the interacting dynamics of different aspects of the social network, specifically network structure (size and frequency of contact), social activity engagement, and emotional support, and different aspects of health and subjective well-being in a representative sample of 2034 older adults across 6 years of development. The analysis, using latent change score models, revealed that older age at Time 1 was related to steeper declines in network structure and social engagement, but was unrelated to changes in emotional support. Furthermore, levels of social engagement and levels of emotional support predicted changes in functional health and life satisfaction with equal strength. Changes in social engagement were associated with changes in life satisfaction, positive affect, functional health, and subjective health. Changes in emotional support were only associated with changes in negative affect. Mediation analyses suggested that network structure may stimulate social engagement and emotional support, thereby exerting indirect influences on key aspects of successful aging. The results underscore the importance of considering the multifaceted nature of social relations in understanding their impact on distinct developmental goals, and across different domains of successful aging.