Posttraumatic stress disorder (PTSD) commonly co-occurs with other disorders. Although there are several evidence-based treatments available for PTSD and co-occurring disorders, including cognitive processing therapy (CPT), prolonged exposure (PE), acceptance and commitment therapy (ACT), and the unified protocol for transdiagnostic treatment of emotional disorders (UP), limited findings clarify the use of baseline symptom data to help providers and patients choose among treatments. To address this, the current study examined baseline symptoms and treatment trajectories among 90 veterans and veteran family members with probable PTSD (based on PCL-5) receiving either trauma-focused (CPT, PE) or transdiagnostic (ACT, UP) treatment via telehealth, with the aim of assisting providers in recognizing patterns to inform data-driven treatment selection. Overall, there was no difference in the likelihood of clinically meaningful improvement in PTSD symptoms between transdiagnostic and trauma-focused treatments, relative risk (RR) = 0.92, 95% confidence interval (CI) [0.63, 1.34]. When stratified by probable substance use disorder (SUD) and major depressive disorder (MDD) status, the results revealed a pattern suggesting that transdiagnostic treatment may be more effective for reducing PTSD symptoms among individuals with probable co-occurring SUD and MDD, RR = 1.50, 95% CI [0.27, 8.34], whereas trauma-focused treatment may be more effective for those without probable co-occurring SUD or MDD, RR = 0.56, 95% CI [0.31, 1.00]. Studies with larger samples and randomization are needed to confirm patterns. This work could be extended by comparing outcomes from other treatments and by assessing functional outcomes such as posttraumatic growth and quality of life.