BACKGROUND: Home-Based Primary Care (HBPC) has demonstrated success in decreasing risk of hospitalization and improving patient satisfaction through patient targeting and integrating long-term services and supports. Less is known about how HBPC teams approach social factors. OBJECTIVE: Describe HBPC providers' knowledge of social complexity among HBPC patients and how this knowledge impacts care delivery. DESIGN, SETTING, AND PARTICIPANTS: Between 2018 and 2019, we conducted in-person semi-structured interviews with 14 HBPC providers representing nursing, medicine, physical therapy, pharmacy, and psychology, at an urban Veterans Affairs (VA) medical center. We also conducted field observations of 6 HBPC team meetings and 2 home visits. APPROACH: We employed an exploratory, content-driven approach to qualitative data analysis. RESULTS: Four thematic categories were identified: (1) HBPC patients are socially isolated and have multiple layers of medical and social complexity that compromise their ability to use clinic-based care; (2) providers having "eyes in the home" yields essential information not accessible in outpatient clinics; (3) HBPC fills gaps in instrumental support, many of which are not medical; and (4) addressing social complexity requires a flexible care design that HBPC provides. CONCLUSION AND RELEVANCE: HBPC providers emphasized the importance of having "eyes in the home" to observe and address the care needs of homebound Veterans who are older, socially isolated, and have functional limitations. Patient selection criteria and discharge recommendations for a resource-intensive program like VA HBPC should include considerations for the compounding effects of medical and social complexity. Additionally, staffing that provides resources for these effects should be integrated into HBPC programming.