Purpose: This study sought to identify the policies and guidelines regarding culturally competent care of sexual and gender minority (SGM) cancer patients and survivors at National Cancer Institute (NCI)-Designated Comprehensive Cancer Centers. Methods: This study used an in-depth interview qualitative approach. Semistructured interviews were conducted via telephone with representatives from 21 of the 45 NCI-Designated Comprehensive Cancer Centers in 2015. Verbatim transcripts were created from the audiotapes for content analysis. Results: Two main themes were identified as follows: (1) patient-focused experiences and support and (2) organization-focused development activities. Most of the cancer centers in this study had an advisory committee to assist with SGM policies and guidelines. Despite the existence of these committees, the majority of centers did not have explicit policies, guidelines, or routine practices addressing the following issues: the collection and integration of sexual orientation and gender identity information in the medical record, gender-neutral language on patient forms, patient educational materials with SGM-specific health concerns, SGM-specific support for cancer survivors, or required SGM-specific cultural competency trainings for medical and nonmedical staff. Conclusion: In general, the cancer centers in this study lacked institutional policies, guidelines, and practices focused on patient-centered cancer care for SGM populations. Coordinated efforts are needed to systemically improve patient-centered cancer care for these populations.