Introduction Although an understanding of the patient work system has been increasing in the field of Ergonomics and Human Factors, the role of informal caregivers (unpaid, nonprofessional caregivers) within the patient work system remains largely unexplored (Holden, Schubert, & Mickelson, 2015; Holden, Valdez, Schubert, Thompson, & Hundt, 2017). Informal caregivers include the family members and friends of persons with dementia (PwD), or anyone else who is unpaid, and a non-professional caregiver for a PWD(Reinhard, Given, Petlick, & Bemis, 2008). Nevertheless, informal caregivers are often unsupported and lack guidance with caregiving activities(Alrashed, 2017; Bossen, Christensen, Grönvall, & Vestergaard, 2013). This study represents a first step to define the work of informal caregivers, identify variations in caregiver involvement across multiple caregivers, and explore the perceptions of the primary caregiver (PC) regarding the care network. Understanding the specific roles and work associated with providing care can help us to support and prepare future and current informal caregivers on how to overcome barriers in the work system and increase quality of care for the PwD. Methods Semi-structured interviews were used to encourage 20 self- identified primary caregivers to discuss their daily experiences in providing care to a PwD. Interview questions related to: 1) the daily activities of informal caregivers; 2) the strategies, tools, and resources used and developed by informal caregivers to manage caregiving responsibilities; 3) unmet needs in providing care; and 4) the context in which informal caregiving occurred. We used a thematic analysis with the goal of understanding informal caregiving roles in the PwD work system. Guided by the research questions, structural coding of passages in the transcripts was performed by two members of the research team. The team also mapped the caregiver networks to understand the differences in each role network level. Results The results revealed that the work of informal caregivers of PwD consists of a wide range of tasks that can be physically challenging as well as mentally and emotionally burdensome. Our analysis also revealed distinct variations in care networks and primary caregiver perceptions of other themes: 1) informal caregivers operate at three role levels of care within the care network; 2) PwD care networks vary greatly in size and relationships, and 3) PCs act as gatekeepers to the care network. Caregivers were mapped across three levels of the PwD's care network based on frequency of interactions with the PC and PwD, communication patterns, and contributions to the care activities. Care networks varied between 2 and 11 caregivers who contributed to the care activities in some capacity. The relationships between caregivers and PwD varied greatly, including spouses, children, siblings, neighbors, and volunteers. Further, we found that there is usually one PC for every PwD. The PC acts as a gatekeeper to the care network by regulating interactions between other caregivers and the PwD. The PC also had different expectations for each caregiver based on their relationship to the PwD. Discussion This research presents preliminary findings on the roles of informal caregivers of persons with dementia. These results warrant further investigation into role delineation, primary, secondary, and tertiary caregiver expectations, and the full conceptualization of caregiver work. A formal network analysis that maps caregiver activities to specific roles may be beneficial to understand all the contributions to the care network. These findings are valuable to inform patient work system design in informal care settings. Currently, there is a lack of guidance on how informal caregivers should coordinate care for patients with chronic illness in their homes, and a lack of support for these informal care activities. Defining caregiver work and understanding caregiver perceptions of work can pave a path towards designing better patient work systems to connect the network more efficiently, while improving care quality in informal settings.