Background: Lesbian, gay, bisexual, transgender, non-binary, queer/questioning, and other sexual/gender minority (LGBTQ+) Veterans have disproportionate risk for poor mental health outcomes and suicide. Despite advances in VHA LGBTQ-affirmative care, systemic discrimination and barriers to accessing affirmative mental health care continue to exacerbate mental health disparities. LGBTQ-Affirmative Cognitive Behavioral Therapy (CBT) is a unique intervention with a strong evidence base for improving mental health among LGBTQ+ individuals. This intervention is ready for implementation, but it has not yet been implemented widely in VHA. Additionally, despite models and frameworks focusing on the intersection of health equity and implementation science, there is a lack of empirical evidence testing the impact of equity-focused implementation strategies. Significance: Points of significance include: 1) High rates of suicide among LGBTQ+ Veterans and few evidence-based solutions for this population, 2) Focus on LGBTQ+ equity and collaboration/power-sharing, both of which are part of the VHA Strategic Plan, and 3) Strong partnerships with operations partners and Veteran-led community partners to enable quick action on study findings. Innovation & Impact: Points of innovation include: a) First known study to test implementation of an LGBTQ- affirmative mental health treatment within VA or the broader community, b) Unique emphasis on power-sharing and participatory methods to incorporate health equity into rigorous implementation science methodology, and c) First known clinical trial to leverage a validated natural language processing-based algorithm to identify an electronic, administrative cohort of LGBTQ+ Veterans to test effectiveness outcomes. Specific Aims: The objective of this project is to use a hybrid type III implementation-effectiveness trial design to test provider-level and Veteran-level outcomes associated with an Equity-Focused Implementation Package to increase adoption and sustainment of LGBTQ-Affirmative CBT. The study includes the following specific aims: 1) to refine an Equity-Focused Implementation Package for improving uptake of LGBTQ-Affirmative CBT; 2a) To conduct a multi-site cluster-randomized trial of 12 facilities comparing a Standard Implementation Package to an Equity-Focused Implementation Package; 2b) To qualitatively examine equity-related determinants of implementation across sites; and 3) To estimate the reach and effectiveness of the Equity- Focused Implementation Package among LGBTQ+ Veterans between implementation arms. Methodology: This cluster-randomized trial will include 12 facilities randomized 1-to-1 to receive either a Standard Implementation Package (train-the-trainer, access to self-guided training, free treatment manuals, and national consultation calls) or an Equity-Focused Implementation Package (Standard Implementation plus 6 equity-focused implementation strategies). The primary implementation outcome is ...