For a study, researchers sought to understand the differences in baseline patient-reported outcome measures (PROMs) among patients with lumbar spinal stenosis (LSS) related to insurance type. According to previous studies, patients who were more socioeconomically disadvantaged reported lower baseline PROMs. However, this link has yet to be investigated in patients with spinal stenosis. About 608 people with LSS were found in a large academic health institution. The results of their baseline Patient-Reported Outcomes Measurement Information System for physical function, pain, anxiety, and depression, as well as their visual analog scale for low back and leg pain, were examined. For descriptive non-adjusted comparisons, Wilcoxon rank-sum and chi-squared tests were used. PROMs were used as dependent variables, insurance type was used as the key predictor, and all other variables (such as the Charlson Comorbidity Index, age, gender, race, ethnicity, language spoken, and median geographic household income) were used as covariates. The cohort’s average age was somewhere between 62.6 ± 14years, with a female preponderance (50.7%). Patients with Medicaid insurance were younger, Hispanic, and less likely to speak English than those with private or Medicare insurance. Patients with Medicaid insurance had lower baseline PROMs in almost every domain, with Patient-Reported Outcomes having the lowest performance. Physical global (incidence rate ratio 0.88, 95% CI 0.82–0.95) and mental function (incidence rate ratio 0.85, 95% CI 0.80–0.92) were measured using the Measurement Information System 10. Even after controlling for covariates, LSS patients with Medicaid have systematically poorer baseline PROMs across almost all domains than those with private insurance or Medicare. These findings have far-reaching consequences for research and healthcare policy, particularly when PROMs are used as value indicators.