Introduction: The DSM-5 Alternative Model of Personality Disorders (AMPD) and the ICD-11 classification of personality disorders (PD) are largely commensurate and, when combined, they delineate 6 trait domains: negative affectivity, detachment, antagonism/dissociality, disinhibition, anankastia, and psychoticism. Objective: The present study evaluated the international validity of a brief 36-item patient-report measure that portrays all 6 domains simultaneously including 18 primary subfacets. Methods: We developed and employed a modified version of the Personality Inventory for DSM-5 - Brief Form Plus (PID5BF+). A total of 16,327 individuals were included, 2,347 of whom were patients. The expected 6-factor structure of facets was initially investigated in samples from Denmark (n = 584), Germany (n = 1,271), and the USA (n = 605) and subsequently replicated in both patient- and community samples from Italy, France, Switzerland, Belgium, Norway, Portugal, Spain, Poland, Czech Republic, the USA, and Brazil. Associations with interview-rated DSM-5 PD categories were also investigated. Results: Findings generally supported the empirical soundness and international robustness of the 6 domains including meaningful associations with familiar interview-rated PD types. Conclusions: The modified PID5BF+ may be employed internationally by clinicians and researchers for brief and reliable assessment of the 6 combined DSM-5 and ICD-11 domains, including 18 primary subfacets. This 6-domain framework may inform a future nosology for DSM-5.1 that is more reasonably aligned with the authoritative ICD-11 codes than the current DSM-5 AMPD model. The 36-item modified PID5BF+ scoring key is provided in online supplementary Appendix A see www.karger.com/doi/10.1159/000507589 (for all online suppl. material).