Social relationships are a well-documented correlate of health and well-being, although emerging research suggests a bleaker side of social support — especially in the face of stress. For older adults, in particular, support may undermine one’s sense of competence and autonomy. Using daily diary data from the 2013 Disability and Use of Time supplement to the Panel Study of Income Dynamics (n=1,474), a national sample of older adults, this presentation will evaluate the extent to which family support and strain moderate the effects of disability-related stress on older adults’ emotional well-being, with attention to gender and marital status differences. The results suggest that older women derive strength from social support, whereas older men feel undermined by it, especially in the face of age-related health declines. Understanding how social relationships enhance or undermine older adults’ daily well-being has important implications for population health and health care practice.