Compared with older adults with disabilities and those who autonomously choose to live in squalor, self-neglect syndrome arises from a predicate state of vulnerability in frail older adults. This state of vulnerability is characteristically associated with a decline in decision-making capacity regarding the ability to care for and protect oneself. We developed the COMP Screen to evaluate vulnerable older adults to identify potential gaps in decision-making capacity using a screening tool. A total of 182 older adults were evaluated and consistent declines in cognitive ability and decision-making processes were present in this population. However, there were no significant differences between elders referred for self-neglect and matched older adults. These findings suggest that declines in decision-making processes are not uncommon in vulnerable older adults but traditional conceptualizations of decision-making capacity may be inadequate for differentiating the capacity for self-care and protection in elders who self-neglect.