ImportanceThe potential role of living alone in either facilitating or hampering access to and use of services for older adults with cognitive impairment is largely unknown. Specifically, it is critical to understand directly from health care and social services professionals how living alone creates barriers to the access and use of supportive health care and social services for racially and ethnically diverse patients with cognitive impairment.ObjectiveTo identify the potential role of living alone in the access and use of health care and social services for diverse patients with cognitive impairment by investigating professionals' perceptions of caring for such patients who live alone in comparison with counterparts living with others.Design, setting, and participantsThis qualitative study of 76 clinicians, social workers, and other professionals used semistructured interviews conducted between February 8, 2021, and June 8, 2022, with purposively sampled professionals providing services to diverse patients with cognitive impairment in Michigan, California, and Texas.Main outcomes and measuresClinicians, social workers, and other professionals compared serving patients with cognitive impairment and living alone vs counterparts living with others. An inductive content analysis was used to analyze the interview transcripts.ResultsA total of 76 professionals were interviewed (mean [SD] age, 49.3 [12.7] years); 59 were female (77.6%), 8 were Black or African American (11%), and 35 were White (46%). Participants included physicians, nurses, social workers, and home-care aides, for a total of 20 professions. Participants elucidated specific factors that made serving older adults living alone with cognitive impairment more challenging than serving counterparts living with others (eg, lacking an advocate, incomplete medical history, requiring difficult interventions), as well as factors associated with increased concerns when caring for older adults living alone with cognitive impairment, such as isolation and a crisis-dominated health care system. Participants also identified reasons for systematic unmet needs of older adults living alone with cognitive impairment for essential health care and social services, including policies limiting access and use to public home-care aides.Conclusions and relevanceIn this qualitative study of professionals' perspectives, findings suggest that living alone is a social determinant of health among patients with cognitive impairment owing to substantial barriers in access to services. Results raised considerable concerns about safety because the US health care system is not well equipped to address the unique needs of older adults living alone with cognitive impairment.