ABSTRACT The clinical utility of the DSM‐5's Alternative Model of Personality Disorders (AMPD) depends on how well it encodes diagnostic concepts recognized in clinical descriptions of PDs. The present study examined the AMPD's coverage of borderline personality features identified in the clinical literature. In three independent samples (total N = 1166), community adults and university students rated their borderline features, level of personality functioning (AMPD Criterion A), and maladaptive personality traits (AMPD Criterion B). We observed that, collectively, the AMPD dimensions accounted for 76%–82% of borderline PD variance across samples. In supplemental analyses that adjusted for measurement error, the variance‐explained range climbed to 84%–96%. Some domains of borderline pathology were better represented than others in the AMPD, highlighting areas for improvement in future iterations of the AMPD and related dimensional nosologies. We conclude that, at least in the populations studied here, the AMPD is a serviceable model of longstanding borderline constructs, providing a bridge from categorical to dimensional conceptualizations of borderline PD.