LGBTQ+ individuals encounter enduring discrimination and adverse healthcare encounters within the healthcare system, with profound implications for their health and wellbeing. Policymakers have advocated for the adoption of LGBTQ+ inclusive and culturally competent healthcare, including training for health professionals, to promote health equity among LGBTQ+ populations. However, implementation of these policies within healthcare systems varies, posing structural and individual-level barriers. In this dissertation, I employ an ecological model of LGBTQ+ health disparities and a conceptual model of determinants of health disparities in vulnerable populations within the healthcare system to examine the impact of structural inequities on the implementation of LGBTQ+ inclusive policies and culturally competent healthcare practices. Through a systematic literature review, I synthesized existing research on LGBTQ+ cultural competency training for health professionals across disciplines and settings. Results indicated that participation in such training is associated with significant improvements in cultural competence, yet notable geographical and institutional disparities exist in their provision. To investigate the association between state and hospital-level factors and LGBTQ+ inclusion and cultural competency in healthcare settings, I conducted secondary data analysis of datasets related to hospital-level LGBTQ+ policies and practices, a hospital’s Magnet status, state laws, political climate, and sociodemographic factors. Findings revealed that the implementation of LGBTQ+ inclusive policies and practices in hospitals is associated with Magnet status, hospital type, and the political landscape at the state level. To delve deeper into the factors influencing implementation, a qualitative descriptive study informed by implementation science theory examined nurse leaders’ perceptions of facilitators and barriers to implementation. Multilevel determinants emerged, including state-level political climate and LGBTQ+ laws, organizational commitment to diversity, equity, and inclusion, leadership engagement, and LGBTQ+ community engagement. The results of this dissertation underscore the need for an ecological understanding of LGBTQ+ health disparities to effectively implement LGBTQ+ inclusion efforts in healthcare settings. Addressing inequities in healthcare policies and practices should prioritize initiatives aimed at mitigating legal constraints faced by LGBTQ+ individuals. Moreover, fostering collaboration among healthcare systems, academic institutions, and LGBTQ+ community organizations is crucial for ensuring equitable access to inclusive and affirming healthcare services for all.