Age-related declines in cognition on standard neuropsychological tests are associated with intrinsic functional changes to the default mode network (DMN; Nashiro et al., 2017). Regions in this network also show increased atrophy compared to the rest of the cortex with advancing age (Fjell et al., 2014). However, recent advances in the fields of social and affective neuroscience demonstrate that age-related declines in cognition and DMN structure and function may not always extend to socioemotional domains, especially when tasks involve internal deliberation (Andrews-Hanna et al, 2019). Rather, changes in DMN architecture may reflect age-related adaptive processes in social and emotional domains. Similar to standard neuropsychological tasks, moral decision-making is associated with regions involved in the DMN including its two main hubs the medial prefrontal cortex (mPFC) and the posterior cingulate cortex (PCC; Green, 2001; Green et al., 2004). Healthy older adults have acted as control groups for assessing neural changes associated with moral decision-making abilities in individuals with neurodegenerative disorders, but the relationship between their DMN structural and functional integrity and performance on moral decision-making tasks have not been directly compared to younger adults. Thus, it is unclear how advancing age is associated with these relationships. Here we seek to clarify three aims: 1) To determine how strongly the gray matter structure of the mPFC and PCC, core nodes of the DMN, differentially predict performance on working memory or moral decision-making tasks in young and older adults; 2) To assess whether the variability in behavioral performance can be predicted by resting-state functional connectivity over and above structural metrics.