Korean employs case ellipsis (CE), in which nouns are permitted to appear without case markers in certain contexts, particularly in informal settings. Heritage speakers (HS) are typically exposed to informal registers and thus exposed to fewer uses of overt case markers in the input. Given the limited exposure, it is predicted that young HS of Korean will not have control over CE. Three Korean heritage children were observed longitudinally over two years. Findings revealed that all three of the children use CE from as early as 3;09. The results also show no decrease of the use of CE over two years and that CE appears more frequently with canonical word order and deixis terms, patterning similarly to other Korean speakers. Despite the fact that the children predominantly hear Korean spoken in informal registers and the data were collected during informal, low register contexts, the children exhibit competence of CE.