Explanatory Particularism in Scientific Practice offers a novel community-centric account of scientific explanation. On this view, explanations are products of collaborative activity in particular communities. Philosophers of science studying explanation have traditionally seen their task as analyzing the common or fundamental core of explanations across the sciences. Melinda Bonnie Fagan takes the opposite view: diversity of explanations across the sciences is a basic feature of scientific practice. A scientific community produces explanations that advance understanding of some target of interest, but just what features advance understanding, and what understanding amounts to in practice, varies widely over time and across scientific communities. This particularist approach brings new problems and questions to the fore, especially concerning interdisciplinarity: how (if at all) do explanation and understanding get beyond the boundary of a particular community? The particularist account also has implications bearing on the nature of understanding, the unity of science, objectivity, and science-society relations. The argument is elaborated using detailed case studies of explanatory model connection, or lack thereof: immunology and epidemiology models in the COVID-19 pandemic and the explanatory ambitions of systems biology, using the example of stem cell development. The argument concludes with an open-ended list of potential future case studies.