The current study investigates heritage language (HL) learners’ production of the Korean three-way stop contrast. Korean consonants include a typologically rare distinction among three types of voiceless stops typically described as plain /p, t, k/, aspirated /ph, th, kh/, and tense /p*, t*, k*/. This study examines how this phonological contrast is implemented by HL learners enrolled in a beginning level Korean class at a university. Language-specific (i.e., English and Korean) gender effects in VOT are also explored in HL learners. The results show that voice onset time (VOT) mainly serves to differentiate tense stops from plain and aspirated stops, while f0 plays a significant role in differentiating plain from aspirated and tense stops in HL learners. This finding is consistent with accounts of sound change under way in current Korean stops. The inter- and intraspeaker variations or categorical confusion with Korean plain stops commonly shown in second language (L2) learners is not found in HL learners of this study. Hence, the results of the present study support the view that HL learners preserve the phonological and phonetic benefits in their HL. In terms of gender-based differences, VOT is found to be shorter for males in plain and aspirated stops, while it is longer for males in tense stops. Finally, this study also suggests that controlling the heterogeneity of subjects mitigates the methodological challenges of HL research.