Abstract: Brenner et al. (2021) developed and initially tested two computerized adaptive measures of posttraumatic stress disorder (PTSD), one that provides a provisional diagnosis (PTSD computerized adaptive diagnostic screen [CAD-PTSD]) and one that estimates symptom severity (PTSD computerized adaptive severity test [CAT-PTSD]). We expanded on the initial psychometric findings by collecting data regarding test–retest reliability, incremental validity, and respondent burden. A sample of veterans (N = 156, 32% women, 36% Black, 13% identified as Spanish, Hispanic, Latino, Puerto Rican, or Cuban) recruited from three Veterans Affairs medical centers completed the CAT-PTSD and CAD-PTSD, the Clinician-Administered PTSD Scale for DSM-5, the PTSD Checklist for DSM-5 (PCL-5), Primary Care PTSD Screen for DSM-5 (PC-PTSD-5), and a battery of other self-rated scales. Fifty-three participants (34%) completed the measures a second time within 7 days (Mdays = 5.41; SD = 1.97) of their first visit. CAT-PTSD scores revealed good convergent validity (r = .78 with Clinician-Administered PTSD Scale for DSM-5 total score), discriminant validity, and test–retest reliability (r = .80). Scores on the PCL-5 and PC-PTSD-5 had similar characteristics. The CAD-PTSD demonstrated poor diagnostic efficiency, κ(.5, 0) = .40, and test–retest reliability (κ = .25), whereas previously established cut-scores for the PCL-5 and PC-PTSD-5 showed fair to good diagnostic utility and adequate to good test–retest reliability. Results suggest that the CAT-PTSD may provide a valid indicator of PTSD symptom severity, but does not offer incremental value beyond the PCL-5 and PC-PTSD-5. The CAD-PTSD was markedly inferior to the use of PCL-5 or PC-PTSD-5 cut scores.