For motor vehicle crashes, we estimated the medically related costs of nonfatal injury by body region and severity. Our primary data sources were paid charges reported in the Detailed Claims Information data base of the National Council on Compensation Insurance and injury incidence and severity reported in the National Highway Traffic Safety Administration's National Accident Sampling System (NASS). Brain and lower extremity injuries account for the largest portion of medical costs. Spinal cord and severe brain injuries cost more per case. Our average costs per case are very close to those in a report to Congress but come from completely different data sources. Thus, national data bases are providing consistent medical cost estimates.