Approximately 70% of individuals worldwide and 83% of individuals in the United States report trauma exposure in their lifetime, and 5.6 and 8.3%, respectively, will go on to develop posttraumatic stress disorder (PTSD; (Koenen et al. Psychological medicine 47:2260–2274, 2017)). Trauma-focused CBT for PTSD has a strong evidence base, and there are notable barriers to treatment including access to mental healthcare, access to trained providers, avoidance, mistrust, and shame. Among those who do engage in treatment, many drop out prior to completing enough sessions to benefit (Schnurr et al., JAMA network open 5:e2136921, 2022). In addition, some clients do not fully remit even after receiving an adequate dose of these treatments. This chapter will provide an overview of the literature on treatment engagement in PTSD including review of cognitive, behavioral, and system barriers to treatment; predictors of engagement; dropout and nonresponse from CBTs; and the consequences of underutilization and engagement in treatment for individuals with PTSD. Additionally, this chapter will discuss clinical considerations and strategies for engaging individuals with PTSD in cognitive behavioral therapies.