The proposal of five dimensions of social well-being, social integration, social contribution, social coherence, social actualization, and social acceptance, is theoretically substantiated. The theoretical structure, construct validity, and the social structural sources of the dimensions of social well-being are investigated in two studies. Item and confirmatory factor analyses in both studies corroborate the theoretical model of social well-being. The new scales correlate convergently with measures of anomie, generativity, perceived social constraints, community involvement and neighborhood quality. The new scales correlate discriminantly with measures of dysphoria, global well-being, physical health and optimism. Multivariate analyses in both studies substantiate the claim that social well-being is an achievement, facilitated by educational attainment and age. The state and direction of the study of adult functioning are discussed.