In this article, we examine the coverage of immigrant civil society in a widely-used 501(c)3 database. We estimate the organizational undercount for four immigrant communities (Indian, Mexican, Portuguese and Vietnamese) across seven cities in Silicon Valley, using interviews with 160 key informants and community leaders and extensive examination of directories, databases and media (ethnic and mainstream). Focusing on publicly present non-profit organizations, we ask whether under-representation and undercounts of nonprofit organizations impact some migrants groups more than others, and whether patterns vary by type of city or organizational activity. We find substantial under-representation and organizational undercount across our four groups and seven cities. Representation is particularly worse in smaller cities, and the undercount especially affects attempts to accurately enumerate Mexican organizations. These findings have implications for resource inequalities and advocacy among minority communities, and for accurately judging the vitality of immigrant civil society when relying on standard 501(c)3 data sources.