The Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 Section III alternative model of personality disorder (AMPD) was developed to rectify some of the failings of the DSM-IV personality disorders, including a lack of compelling discriminant validity. The primary purpose of the current study was to provide a direct comparison of DSM-IV with DSM-5 Section III AMPD with respect to discriminant validity in a sample of 302 community members from the United States who were currently receiving or had received mental health treatment. The AMPD Criterion A, level of personality functioning, was assessed by the Section III Criterion A impairment scales (Anderson & Sellbom, 2018). AMPD Criterion B, the five-domain pathological trait model, was assessed by the Personality Inventory for DSM-5 (Krueger, Derringer, Markon, Watson, & Skodol, 2012). Also included was the cross-cutting Level of Personality Functioning Scale-Self Report (Morey, 2017). DSM-IV personality disorders were assessed by the Personality Diagnostic Questionnaire-4 (Hyler, 1994) and the Multi-Source Assessment of Personality Pathology (Oltmanns & Turkheimer, 2006). Results demonstrate no substantive improvement in discriminant validity in the AMPD compared to the DSM-IV. Implications of these findings for the conceptualization and assessment of personality disorders are discussed. (PsycInfo Database Record (c) 2020 APA, all rights reserved).