Our study advances knowledge in this area by providing MID estimates for WHODAS-12 specific to persons with chronic LBP. Our findings have potential implications for measuring functioning for chronic LBP related to rehabilitation services. This helps to guide management and effective rehabilitation care using WHODAS-12 as an outcome measure. Moreover, our findings may inform sample size considerations for future RCTs focused on measuring functioning in samples with chronic LBP. We analyzed data from two cohort studies conducted in Europe to compute two estimates of MID for WHODAS-12 in adults with chronic LBP.