The objectives of this study were to develop and validate an equal-interval measure of neurologic impairment from the International Standards for Neurological and Functional Classification of Spinal Cord Injury Patients developed by the American Spinal Injury Association. These standards were used to rate impairment at admission and discharge to Model System facilities. The results demonstrate that the standards fulfill their purpose of characterizing sensory-motor impairment. Developed was a self-scoring key that rehabilitation clinicians can use to obtain a measure of severity that combines sensory and motor level ratings and completeness classifications to describe impairment more precisely and illustrate the magnitude of reductions in impairment. This measure can be used to monitor improvement over time and compare severity across individuals or groups.