Korean exhibits a phenomenon known as case stacking, where a single nominal can bear two markers traditionally associated with case. We show that while the inner markers in stacked nominals reflect genuine case, the outer markers are instead associated with discourse marking. Stacked “nominative” and “accusative” are in fact focus markers, whose distributions are distinct from those of genuine case marking (Schütze 2001). We propose that the inner markers are associated with the argument introducing heads Voice and Appl, and the outer markers are associated with focus and topic. By assigning inner markers low and outer markers high, our analysis derives the templatic ordering of morphemes in Korean nominals (Cho & Sells 1995) and explains the difference in distribution of honorific nominative (HON.NOM) and plain nominative (NOM). Our analysis that only external argument introducing heads (Voice and Appl) can assign honorific-sensitive case markers captures an independent fact about Korean: the case paradigm contains HON.NOM and HON.DAT but no *HON.ACC.