Role of Home-based Medical Care and Telemedicine in Care and Outcomes of Dementia and Coexisting Conditions in Public and Private Medicare - Home-based medical care (HBMC) is essential for the growing population of community-living persons with Alzheimer's Disease and Related Dementias (ADRD). People living with ADRD (PLWD) often also have multiple chronic conditions that necessitate complex care regimens, but as functional impairment worsens, PLWD may struggle to leave home to access medical care. HBMC then becomes instrumental in enabling continuity of patient care, tailoring medical management to evolving patient needs and risks and mitigating the caregiving burden. HBMC is provided by physicians and advanced practice providers and has long been covered by public (Fee for Service) Medicare. Due to its limited availability, there are likely many more people who may benefit from HBMC than there are persons who receive HBMC. Two changes in the Medicare landscape over the last decade may significantly alter access to and outcomes from HBMC for PLWD: rapid enrollment and switch to private (Medicare Advantage) plans and the swift expansion of telemedicine use since early 2020. Our study aims to examine HBMC use among PLWD with private and public Medicare, its change following the expansion of telemedicine, and its overall impact on patient outcomes and disparities. While the rationale for HBMC is compelling, evidence of its impact on PLWD is scant. Evidence of differences in healthcare utilization patterns between private and public Medicare enrollees is recent and evolving, particularly for PLWD, with virtually no prior work on patterns of HBMC use. HBMC providers can combine home visits with telemedicine services and expand the scale and range of services. The extent to which these have occurred in public and private Medicare is unclear. Using national Medicare administrative data (2017-2023) covering public and private Medicare enrollees with PLWD, we propose to fill the significant evidence gaps by identifying the national trends in HBMC and telemedicine use and rigorously evaluating their potential impact on the management and outcomes for community living PLWD. Our main outcomes will be indicators of treatment for ADRD, deprescribing long-term medications, acute care complications, proportion of days at home, transition to long-term care and hospice, death, and healthcare spending. Using quasi-experimental models of causal inference, we will estimate the potential impact of HBMC (before and after the expansion of telemedicine) and telemedicine, separately in public and private Medicare. We will estimate the impact across subgroups by sex, race, ethnicity, dual Medicaid eligibility, multiple chronic conditions and, provider quality performance. PLWD have complex medical needs with high mobility and transportation barriers, and HBMC and telemedicine may be vital avenues to facilitate better care continuity, alleviate patient and caregiver burden, and improve patient outcomes. Our findings aim to develop rigorous, generalizable, and policy-oriented evidence on the potential impact of HBMC and telemedicine for PLWD.