Cognitive Processing Therapy (CPT) has accumulated substantial empirical support demonstrating its effectiveness in the treatment of post-traumatic stress disorder (PTSD) over the last three decades. However, like many manual-based protocols, implementation in real-world clinical settings is subpar, in part due to the lack of guidance within the protocol for addressing the universe of clinical complexities that may emerge during therapy and contribute to suboptimal outcomes or premature dropout. Poor engagement, comorbid mental and physical health conditions, major life stressors, emotional dysregulation, and treatment-interfering avoidance behaviors can make it challenging to apply standardized treatment protocols like CPT effectively. Personalization of the CPT protocol with a case formulation approach allows the clinician to flexibly apply CPT to address the universe of possible clinical complexities that may arise during therapy and reduce its effectiveness, while maintaining fidelity to the protocol. Specifically, this chapter introduces the Personalized Approach to Therapy (PATh) model, which integrates case formulation into CPT to guide clinicians as they identify and address Challenges to Optimal Therapy Outcomes (COTOs). By providing a structured but flexible framework, PATh guides the clinician in modifying the protocol when necessary to meet the idiosyncratic needs of the patient presenting to clinical care with the overarching goal of moving the needle further toward recovery for more trauma survivors.