Social determinant of health (SDOH) data are essential to individualized care and reducing health disparities. However, there is little standardization in the way that SDOH data are collected, and barriers to increasing the collection of such data exist at both the patient and clinician levels. To evaluate clinician, patient, and care partner perspectives on the barriers to and facilitators of patients sharing SDOH information with their clinicians. This qualitative study included clinicians, patients, and care partners across the United States. Focus groups were conducted between September 2022 and February 2023 to understand the experience of collecting, documenting, and exchanging SDOH data. Rapid assessment procedures were used to analyze focus group transcripts, creating summaries, codes, and themes mapped directly to the project research questions. A total of 235 individuals participated, including 109 (46.4%) clinicians (60 [55.0%] male; 25 [22.9%] Asian, 2 [1.8%] Black, and 74 [67.9%] White) and 126 (53.6%) patients and care partners (45 [35.7%] male; 1 [0.8%] Asian, 48 [38.1%] Black, and 64 [50.8%] White). Clinicians and patients agreed that SDOH data are important for clinicians to know. Both clinicians and patients wanted a structured, standardized way to collect SDOH data in the future, accompanied by time for more in-depth discussion during the visit. However, they highlighted numerous issues that impact collecting these data, including beliefs about how the information will be used, the clinician-patient relationship, having enough of the right staff, time needed to collect SDOH information, and technology used to collect the data (eg, usability, standardization). This qualitative study of the experience of collecting, documenting, and exchanging SDOH data underscores the ongoing barriers to widespread adoption of uniform approaches to SDOH data documentation as well as factors that may help lower those barriers, such as trusting patient-clinician relationships, greater transparency in how the data will be used, and targeted resources. A multifaceted approach to addressing the concerns raised by clinicians, patients, and care partners is required to ensure that such data can be captured in a way that improves care and allows for progress toward an equitable health care system.