Background. Differentiated service delivery (DSD) for HIV care, an approach to better serve clinical and social needs among people living with HIV (PLWH), has been adopted to improve adherence and retention in care. The current DSD programs include four different categories (within-facility individual, out-of-facility individual, provider-managed group, client-managed group). Studies have so far shown mixed results of DSD relative to conventional ART delivery. In 2021, the World Health Organization revised its guideline to expand DSD to offer more individualized HIV services to all PLWH. Currently, DSD individualization is often based on clinical stability or availability of human resources, rather than patient preferences and needs. As countries expand DSD, preference-based individualization of DSD could improve health outcomes and quality of life. This K01 provides a unique opportunity to address these research gaps. Candidate Overview. My long-term career objective is to become an independent investigator who specializes in incorporating patient-centeredness into health programs for PLWH in low- and middle-income countries. While I have developed research skills in epidemiology, statistical methods, discrete choice experiments and preference assessment, this K01 award will provide the necessary additional training and experience to be an independent investigator in the design and evaluation of patient-centered health programs to improve clinical outcomes and quality of life among PLWH and inform policy decision-making. Career Development and Training Plan. My educational program includes structured coursework, professional conferences, directed readings, and a research project with specific aims timed to coincide with these activities. My mentorship team includes international experts who specialize in areas related to my training goals: Dr. Scott Braithwaite (decision science and comparative effectiveness), Dr. Anna Bershteyn (agent-based mathematical modeling), Dr Carolyn Berry (qualitative research), Dr. Elvin Geng (implementation science), and Dr. Elizabeth Bukusi (study execution and dissemination in Kenya). Environment. NYU School of Medicine provides an exceptional environment to conduct the proposed study, obtain additional training and mentorship, and successfully transition to an independent investigator. Research Strategy. My study will evaluate the impact of preference-concordant programs on patient and population outcomes using a prospective cohort study and mathematical modeling in western Kenya. Specifically, the study will: 1) measure the trade-offs that patients are willing to make among different features of DSD programs and how these preferences vary by patient characteristics; 2) determine how preference- concordant DSD programs impact retention, adherence, and viral load suppression; 3) estimate the long-term health impact and costs of preference-concordant DSD programs using mathematical modeling.