Abstract: Trauma-focused psychotherapy is the front-line treatment option for posttraumatic stress disorder (PTSD); however, approximately two thirds of veterans who initiate such evidence-based psychotherapy (EBP) for PTSD discontinue treatment before completing an adequate number of therapy sessions. We examined the association between whole health (WH) care, comprising WH services (e.g., health and wellness coaching, wellness groups) and complementary and integrative health (CIH) therapies, and EBP completion for PTSD. We completed a national retrospective database analysis of Veterans Health Administration administrative records for veterans with PTSD who initiated an EBP in Fiscal Years 2018–2022 and estimated multiple logistic regression models assessing the association between WH care use and EBP completion (i.e., completing eight EBP sessions within 14 weeks). We identified 100,177 veterans with PTSD who initiated EBP (34.8% completed EBP). Of these veterans, 9,824 (9.8%) had used WH services, and 3,396 (3.6%) had used CIH therapies. When controlling for demographic and health-related variables, WH care use was associated with increased odds of EBP completion. The strongest associations were between the use of WH services both before EBP initiation and concurrent with EBP use, OR = 1.39, 95% CI [1.28, 1.51], and the use of CIH therapies concurrent with EBP use, OR = 1.38, 95% CI [1.20, 1.60], or both before EBP initiation and concurrent with EBP use, OR = 1.30, 95% CI [1.17, 1.45]. The results suggest that parallel use of WH care may bolster patient completion of EBP for PTSD, a critical component of the effectiveness of these psychotherapies.