The goals of this study were to (i) examine the association of social support and strain with psychological well-being and health, (ii) investigate whether these associations depended on relationship-type (partner, family, friend), (iii) examine the buffering effects of support on strain (both within and across relationship-type), and (iv) test the extent to which these associations differed by age and sex. The sample contained 2,348 adults (55% male) aged 25 to 75 years (M = 46.3), who were married or cohabitating. Positive and negative social exchanges were more strongly related to psychological wellbeing than to health. For both sexes, partner support and strain and family support were predictive of well-being measures; partner strain was also predictive of health problems. However, family strain was predictive of well-being and health outcomes more often for women. Further, while we did find evidence that supportive networks could buffer the detrimental effects of strained interactions, friends and family served a buffering role more often for women than for men.