Borderline personality disorder (BPD) is serious, prevalent, and symptomatically heterogeneous. Identifying distinct phenotypes of BPD features promises useful diagnostic and treatment implications. Although a series of subtyping studies exist, only two have examined BPD symptom configurations while taking into account BPD severity. We used factor mixture modeling to identify discrete subtypes of BPD features, simultaneously considering symptom severity, in the largest nonclinical young adult sample to date. Undergraduates (N= 20,010; 63.86% women; M age= 18.75, SD= 1.73) completed the McLean Screening Instrument for BPD, which was condensed to measure the 9 Diagnostic and Statistical Manual of Mental Disorders BPD criteria dichotomously. We used a model comparison approach to determine the optimal latent factor and class structure of BPD symptoms and validated classes via BPD-relevant …