This pilot study examined whether posttraumatic stress disorder (PTSD) was associated with increased health costs following severe injury caused by motor vehicle accidents. Three groups of injury survivors were created from a larger sample—PTSD only, no-PTSD–low physical function, and no-PTSD–high physical function—and these groups were compared on health cost outcomes at 12 and 24 months. The presence of PTSD was associated with increased total health costs for both Year 1 and Year 2. However, PTSD, per se, did not independently contribute to total health costs. This study suggests that ongoing physical health problems must be considered in order to accurately assess the unique contribution that PTSD makes to health costs in the physically injured population.