The prevalence of lumbar spinal stenosis is approximately 9.3%, with people most commonly affected in the sixth or seventh decade of life. Patients often have pain, cramping, and weakness in their legs that is worsened with standing and walking. Although the Spine Patient Outcomes Research Trial clearly demonstrated that surgery improves health-related quality of life, treatment for lumbar spinal stenosis varies widely from the type of decompression performed to the need for fusion. This variability can be attributed largely to the lack of an accepted classification system. A good classification system serves as a common language to define the severity of a condition, guide treatment, and facilitate clinical research.