ABSTRACT In 2021, approximately 11 million Americans provided unpaid care to an adult with Alzheimer’s disease and related dementias (ADRD), which was estimated to be 16 billion hours of assistance valued at $271.6 billion. Over 65% of older adults with dementia in the community rely on 2 or more family members or friends to meet their needs, ranging from basic activities of daily living to self-care activities and care decisions. Yet, most caregiving research has been focused on the roles and care burden, including psychosocial and physical health, of a single primary caregiver. Given the aging of the population and the changing demographics of what constitutes a caregiver or care partner in the context of ADRD, the study of caregiving needs to expand to consider the substantial collaboration and co-management that comprises present day caregiving. Our recent study to evaluate the scope and potential impact of informal caregiving networks for older persons with dementia (PWD), using an egocentric social network approach, i.e., based on the informant’s perspective, revealed that there are complex group dynamics and allocation of care activities, including financial obligation, among multiple members of a caregiving network. It also revealed the potential impact of these caregiving networks such that the outcomes of caregivers (e.g., financial hardship) and PWD (e.g., hospital admissions) may be affected by the characteristics of the caregiving network (e.g., member dynamics). In response to NOT-AG-21-047, we propose a longitudinal social network study to capture networks of informal caregiving for 408 PWD and assess the impact of caregiving network characteristics on caregivers’ and PWDs’ health and wellbeing, particularly with regard to the role of social interactions and group dynamics. We will include up to 3 family caregiver informants per network using a multi-informant approach. We estimate that the study will include ~894 family caregiver informants. We will use Social Vulnerability Index scores to ensure a racially and socioeconomically diverse sample of PWD. We will characterize informal caregiving networks by describing network properties (e.g., size, member connectivity), member composition, frequency and type of help the members provide to the PWD, and level of caregiving role distribution. We will examine the extent of changes in network characteristics over 2 years and the impact of the network properties on caregiver and PWD outcomes. Caregiver outcomes will include overall self-rated health, ED visits and hospital admissions, depression, caregiving burden, rewards of caregiving, and financial hardship. PWD outcomes will include ED visits and hospital admissions, proxy-reported quality of life, and changes in living arrangements. Our results will inform strategies for alleviating caregiver burden that take a network perspective into account, such as supporting the community of informal caregivers rather than solely focusing on a pr...