The goal of the present study is to identify a novel paradigm of epistemic modal operator derived from disjunction. Our main data involves an inquisitive disjunction marker nka in Korean, the presence of which enhances a speaker’s epistemic uncertainty and forms a modalized question. We show how nka contributes the modal effects in question within a theory of nonveridicality. In particular, we propose that the prerequisite of nka are non-homogenous nonveridical states that are partitioned in equipoised epistemic spaces because of the absence in ranking between them. The distinct notions of disjunction, question, and possibility modals can thus be systematically captured under the framework of nonveridical equilibrium. The current analysis offers important insights into the relationship between the classes of nonveridical and modal ingredients involved in inquisitive disjunction: First, Korean facts importantly reveal that modalized questions do not form a uniform class with regular questions, since interrogative semantics alone cannot predict the epistemic uncertainty. Second, languages parameterize as to how they lexicalize the function of manipulating modal base. The implication of our findings is that disjunction needs to be recognized as a novel device for encoding a speaker’s weakest perspective on epistemic modality.