Project Abstract Patients who identify as sexual and gender minorities, or LGBTQ+, are critical members of cancer center's catchment areas, yet there remain substantial gaps in providing person-centered care to these patients, most critically because we don't have universal best practices for collecting information to help us identify these patients. Limited data show that members of the LGBTQ+ community are more likely to be diagnosed with late-stage cancer, less likely to receive routine healthcare and screening, less likely to have health insurance, more likely to have higher rates of modifiable cancer risk factors, and more likely to have a lower quality of life compared to their cisgender and heterosexual counterparts. A standardized approach is critical to collect accurate data to best serve the patients' cancer care needs, represent the cancer trends among these patients in cancer registries, address their needs in cooperative group trials, and advocate for equitable funding resources to support relevant research. The overall objective of this project is to understand acceptability, feasibility, as well as assets and challenges around implementation of standardized sexual orientation and gender identity (SOGI) measures at the patient, provider, and organizational level at Roswell Park Comprehensive Cancer Center, a NCI-designated comprehensive cancer center, and to develop and disseminate best practices, lessons learned, and implementation guides with training materials around the importance of expanded SOGI measures through a research-based resource library for other healthcare organizations and comprehensive cancer centers. In the proposed P30 supplement, we will fill several critical gaps by 1) conducting a rigorous evaluation of data quality to understand the impact of modifications made to the Roswell Park electronic health record (EHR) to collect SOGI measures; 2) understanding beliefs and barriers of collecting SOGI information from patients and clinicians to inform development of clinician and patient communications and trainings around these data; and 3) disseminating best practices to accelerate the adoption of these best practices in collection of SOGI measures in cancer care delivery. At the end of this NCI administrative supplement project period, we will have evidence-based recommendations on collecting SOGI data to inform cancer care that meets the needs of this medically underserved community. As a result of this project, Roswell Park will be better positioned to expand this assessment and promote collaborations with our own Roswell Park CARE Network satellite sites across NY and other NCI-designated comprehensive cancer centers. Data capturing SOGI information is vital to understanding how cancer centers, including Roswell Park, can help improve cancer care for sexual and gender minorities and enhance tailored community-based efforts in this population to maximize the effect of cancer prevention, education, and interventio...