Posttraumatic Stress Disorder (PTSD) with co-occurring Borderline Personality Disorder (BPD) (i.e., PTSD-BPD) is common (as high as 58%), debilitating, costly, and limited treatment options available for this population. PTSD-BPD is associated with even greater functional impairment and higher healthcare burden than either disorder alone. There are surprisingly few treatments available for this clinical profile, despite its association with major negative health outcomes, cost, and morbidity. There is a pressing need to innovate treatments that can effectively and efficiently treat PTSD-BPD. The existing treatments used for PTSD-BPD are lengthy, laborious, resource-intensive, and require complete cessation of suicidal behaviors prior to treatment. Furthermore, no integrated treatment has been innovated to deliver the active ingredients to efficiently affect the mechanisms underpinning this comorbidity. The investigators propose to examine an adapted version of a first-line PTSD intervention, Cognitive Processing Therapy, augmented with a Suicide Risk Management, i.e., (CPT+SRM) as a brief (12 sessions) and more parsimonious treatment alternative that strategically targets shared mechanisms underpinning PTSD and BPD. The purpose of this pilot study is to 1) collect initial feasibility, acceptability, and safety data on this adapted treatment, 2) conduct a pilot randomized clinical trial evaluating the efficacy of CPT+SRM versus Treatment as Usual (TAU) + SRM, and 3) evaluate two targets (i.e, improvements in emotional intensity and cognitive dysfunction) as mechanisms leading to change in our primary outcomes. Both treatment conditions will be administered via telehealth. Potential benefits include reduction in participants' PTSD, BPD and other mental health symptoms. Additionally, this work could benefit the community by improving the treatment repertoire for PTSD-BPD. Potential risks include emotional distress, suicidality, and/or self-harm. Participants may experience discomfort and/or distress while discussing participants trauma(s) and mental health. These risks will be mitigated using a suicide risk management protocol which therapists in the assessment of risk and protective factors of suicide, followed by documentation for the decision-making around the management of risk.