This study employed a discourse analysis methodology to compare Korean bilingual students in first and third grades by examining different functions and forms of translanguaging in Korean heritage language classrooms in the U.S. By identifying linguistic functions and forms of each translanguaging occurrence, the study presents that the bilingual students engaged in translanguaging practices in support of their meaning- and sense-making processes. The comparison findings from constant comparative analyses display that the older graders employed translanguaging in more varied forms and for more various purposes than the younger graders because they recognized when to use which language by regulating a higher level of their cognitive thinking skills. The findings provide pedagogical and methodological implications for educators in bilingual education.