How are committee chairs appointed in congresses with null reelection rates and no seniority norms? In this article, I propose an analytical model that draws on informational and distributive theories of legislative organization to explain the logic behind chair appointments during the 21 years of non-majoritarian congresses in the Mexican Chamber of Deputies. Since Mexican legislators are term-limited, and caucus coordinators must select committee chairs among a pool of mostly unknown and inexperienced legislators, this assembly represents an interesting case for challenging the postulates of traditional legislative organization theories. After analyzing chair appointment procedures in the Mexican Chamber through an original database comprising biographical, institutional, partisan and electoral information of 3,470 legislators across seven legislative periods (1997-2018), I have found evidence to sustain that – as long as certain internal and external conditions are met (formal decision-making authority of committees, the absence of a partisan cartel and electoral competitiveness) – merit-based appointments expected by the informative theory, as well as constituent-oriented chair selection proposed by the distributive theory, can be met in congresses lacking reelection incentives and seniority norms.