The goals of this proposal include characterizing the burden, timing, and spectrum of serious infections after HIV+ kidney transplant (KT) with comparison to matched HIV- KT recipients to understand differential risks associated with recipient HIV status (Aim 1). Next, among the population of HIV+ KT recipients, a risk factor analysis will be performed with focus on biological variables and immunosuppressive regimens associated with developing serious post-transplant infections (Aim 2). Finally, the association of donor HIV status with serious infection risk will be explored through the robust infrastructure of the ongoing HOPE in Action multicenter clinical trials of HIV-to-HIV KT (NCT03500315, Aim 3). Taken together, this proposal seeks to delineate the landscape of serious infection among PLWH undergoing KT in the modern era using a comprehensive infection ascertainment schema and rigorous epidemiologic methods. Ultimately, the goal is to advance understanding of infectious complications in this unique and emerging group and drive evidence-based practices that improve long-term post-KT outcomes.