Social ties are powerful predictors of late-life health and wellbeing. Although many adults maintain intimate partnerships into late life, little is known about mental models of attachment to spouses and how they influence aging. Eighty-one elderly heterosexual couples (162 individuals) were interviewed to examine the structure of attachment security to their partners and completed measures of cognition and wellbeing concurrently and 2.5 years later. Factor analysis revealed a single factor for security of attachment. Higher security was linked concurrently with greater marital satisfaction, fewer depressive symptoms, better mood, and less frequent marital conflicts. Greater security predicted lower levels of negative affect, less depression, and greater life satisfaction 2.5 years later. For women, greater security predicted better memory 2.5 years later and attenuated the link between frequency of marital conflict and memory deficits. Late in life, mental models of attachment to partners are linked to wellbeing concurrently and over time.