The hours of unpaid elder care by family members are projected to triple by 2038. Because living with dementia can inhibit decision-making abilities, family members are often besought to assist in this process. In this ethnographic study, relationships within home-based dementia care were critically examined through face-to-face interviews and participant observations with clients, family caregivers, and home care providers (n = 51). The findings revealed how the formalized home care system contextually imposes decisions, and revealed three themes: (1) accommodating clinically defined competence/incompetence, (2) making untimely decisions, and (3) reinforcing exclusion in decision making. These themes shed light on how cultural values (competency), beliefs (immutability of the system), and practices (timing of decisions) of the home care system are ultimately deterministic in decision making for persons with dementia and caregivers. Additional attention to the collaborative and inclusive practices of all family members in dementia home care is imperative in order to optimize health.