This paper leverages recent legislative changes in the Arab Gulf state of Qatar to examine in-group identity and naturalization preferences in the rentier state. In return for greater political autonomy, rentier state leaders distribute some portion of rents to citizens via generous salaries and welfare benefits. Rulers and citizens thus share a material interest in minimizing the pool of citizens-cum-welfare recipients, so as not to dissipate the wealth each enjoys. In the paradigmatically rentier Arab Gulf states, these incentives have given rise to unique systems of naturalization that limit citizenship to an in-group defined by strict ascriptive and temporal criteria. Such criteria provide no pathway to nationality for most rentier residents, including not only the millions of foreign laborers who build and sustain Gulf economies, but also many individuals whose linguistic, racial, and religious identities are indistinguishable from those of citizens. Previous work (e.g., Longva 2006) suggests that it is this drive for economic exclusion—rather than group preferences per se—that underlies identity politics in some Gulf societies. Yet little is known about the preferences of rentier citizens toward naturalization, and how these are shaped by identity factors. While rentier state citizens may tolerate the presence of foreign workers from a diverse set of countries and backgrounds, with which groups, if any, are they willing to share their citizenship privileges? This study uses a conjoint survey experiment to investigate attitudes toward naturalization among citizens of Qatar, a quintessential rentier state. The experimental design builds on the work of Hainmueller and colleagues, who use conjoint analysis to examine preferences toward immigrants in the U.S. (2014) and Europe (2016). In a departure from previous work, this paper examines acceptance of naturalization, or the extension of citizenship, rather than immigration. This choice entails more than the passive tolerance of migrant workers common in Gulf countries: rather, it implies acceptance into a narrowly defined in-group with clear economic and social privileges. The relevance and feasibility of the study are enabled by recent changes in Qatari law that offer the possibility of permanent residence and quasi-citizenship to non-Qataris. We examine the ascriptive and non-ascriptive factors that citizens weigh in judging possible candidates for citizenship, including length of residence, occupation, salary, language, religion, and ethnicity. Results of the experiment will allow us to assess the relative importance of these competing factors and to better understand the complex realities of naturalization in the rentier context.