This article focuses on the problematic relationship between planning experts and society on the basis of the careers of two German architect planners who relocated to the United States during the interwar period: Walter Curt Behrendt (1884-1945) and Oscar Stonorov (1905-1970). Their transatlantic careers highlight the cultural background that shaped planners’ focus on community building and let us trace how technical experts adapted their professional language and re-contextualized their concepts in the process of migration. Across national borders, these experts presented community life as an alternative to urban industrial modernity. Behrendt’s notion of government-backed planning clashed with the realities of the American sociopolitical system. Stonorov, however, developed a planning language focused on participation that was compatible with American democracy. After they had joined ranks in a transnational effort to deal with the consequences of modernization, technical experts like Behrendt and Stonorov re-negotiated their continued presence in all areas of the social in the 1940s and 1950s. This, too, happened in a transnational setting.