Abstract: Purpose: To examine [a] the association of caregiver health-related quality of life (HRQOL) and service member/veteran (SMV) neurobehavioral outcomes with caregiver resilience; [b] longitudinal change in resilience at the group and individual level; and [c] the magnitude of change at the individual level. Methods: Caregivers (N = 232) of SMVs with traumatic brain injury completed a resilience measure, and 18 caregiver HRQOL and SMV neurobehavioral outcome measures at a baseline evaluation and follow-up evaluation three years later. Caregivers were divided into two resilience groups at baseline and follow-up: [1] Low Resilience (<= 45 T, baseline n = 99, follow-up n = 93) and [2] High Resilience (> 45 T, baseline n = 133, follow-up n = 139). Results: At baseline and follow-up, significant effects were found between Low and High Resilience groups for the majority of outcome measures. There were no significant differences in resilience from baseline to follow-up at the group-mean level. At the individual level, caregivers were classified into four longitudinal resilience groups: [1] Persistently Low Resilience (Baseline + Follow-up = Low Resilience, n = 60), [2] Reduced Resilience (Baseline = High Resilience + Follow-up = Low Resilience, n = 33), [3] Improved Resilience (Baseline = Low Resilience + Follow-up = High Resilience, n = 39), and [4] Persistently High Resilience (Baseline + Follow-up = High Resilience, n = 100). From baseline to follow-up, approximately a third of the Reduced and Improved Resilience groups reported a meaningful change in resilience (>= 10 T). Nearly all of the Persistently High and Persistently Low Resilience groups did not report meaningful change in resilience (< 10 T). Conclusion: Resilience was not a fixed state for all caregivers. Early intervention may stall the negative caregiving stress-health trajectory and improve caregiver resilience.