This study examines how selective exposure and interpersonal political disagreement influence political polarization. Using data sets from two countries, the United States and South Korea, this study investigates the association between individuals' selective exposure and attitude polarization and proposes that disagreement in political discussion networks can be a potential moderating variable attenuating the association between selective exposure and polarization. Results across the two nations confirm that individuals' selective likeminded media use is associated with greater polarized attitudes. Findings further show that encountering dissimilar opinions through interpersonal discussion networks generally weakens the association between selective exposure and political polarization, despite some evidence indicating that disagreement leads to more polarized attitudes rather than attenuating polarization. The implications of the findings are discussed.A close relation between people's likeminded media use and political polarization has been demonstrated in the literature-that is, people's consumption of media outlets that share their own political dispositions may lead them to develop more polarized attitudes toward certain issues and political figures (Slater, 2007;Stroud, 2010). Less is known, however, about what factors might attenuate this political polarization process. Although