The National Institutes of Health (NIH) is offering a funding opportunity titled "Ending the Epidemic: New Models of Integrated HIV/AIDS, Addiction, and Primary Care Services (R34 Clinical Trial Optional)." This initiative is focused on developing and testing integrated models of care that enhance the coordination of HIV/AIDS, Hepatitis, and substance use disorder (SUD) services, aimed at improving health outcomes in the U.S. The funding opportunity is a reissue of RFA-DA-25-020 and seeks applications that address gaps in comprehensive health service delivery. Key components of this funding include a maximum award of $450,000 over three years, with the application due dates set for 2024. Research must focus on how to integrate these services effectively in order to address the interconnectedness of these health issues, emphasizing innovative and scalable approaches. Priority will be given to research projects in areas with high HIV burden as identified by the U.S. government initiatives. Eligible applicants include universities, nonprofits, and local governments, among others, and consideration is given to diverse applicants. Investigators are expected to submit their applications via Grants.gov and comply with specific proposal requirements, including adherence to the Data Management and Sharing Plan. This funding opportunity aligns with the broader goal of the U.S. government's "Ending the HIV Epidemic" initiative and aims to facilitate the development of evidence-based care models for individuals at risk or living with these conditions.