Objective To explore stability of relationships and predictors of change in relationship status two years following TBI/Polytrauma. Setting Five Department of Veterans Affairs Polytrauma Rehabilitation Centers (VA PRCs). Participants 357 active duty service members and Veterans enrolled in the VA PRCs Traumatic Brain Injury Model Systems (TBIMS) database with complete marital status information at two-year post-injury. Design Prospective, longitudinal, multi-site. Main Measures Relationship status change was defined as change in marital status (single/never married; married; divorced/separated) at 2-year follow-up, compared to status at injury. Results At the time of injury, 134 participants (38%) were single/never married; 151 (42%) were married, and 72 (20%) were divorced/separated. Of those married at enrollment, 78% remained married at Year 2 while 22% underwent negative change. Multivariable analyses revealed that age and education at the time of injury, and mental health utilization prior to injury, were significant predictors of relationship change. Among those who were single/divorced/separated at the time of injury, 87% remained so at Year 2 while 13% underwent positive change. Injury during deployment significantly predicted positive relationship change. Conclusions The unmalleable, pre-injury characteristics identified may be used as potential triggers for education, prevention, surveillance and couples therapy, if needed.