The goal of this study was to determine the threshold for achieving maximal outcome improvement (MOI) on the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), and Constant-Murley (CM) questionnaires that predict satisfaction after isolated biceps tenodesis without concomitant rotator cuff repair. A retrospective analysis of prospectively collected data was performed for patients undergoing isolated biceps tenodesis from 2014 to 2017 at a single institution with minimum 6-month follow-up. Receiver operating characteristic curve analysis was used to determine thresholds for MOI for the ASES, SANE, and CM questionnaires. Stepwise multivariate logistical regression analysis was performed to identify predictors for achieving the threshold for MOI. A total of 123 patients were included in the final analysis. Receiver operating characteristic analysis determined that achieving 43.1%, 62.1%, and 61.4% MOI was the threshold for satisfaction for the ASES, SANE, and CM questionnaires, respectively. Regression analysis showed that concomitant superior labrum anterior-posterior (SLAP) repair was predictive of achieving MOI on the ASES and SANE questionnaires, whereas partial rotator cuff tear was predictive of achieving MOI on the CM questionnaire (P<.05 for both). Further, workers' compensation status, diabetes, history of ipsilateral shoulder surgery, and hypertension were negative predictors of achieving MOI on the SANE and CM questionnaires (P<.05 for all). Achieving MOI of 43.1%, 62.1%, and 61.4% is the threshold for satisfaction after biceps tenodesis for the ASES, SANE, and CM questionnaires, respectively. Concomitant SLAP repair was positively predictive of achieving MOI, whereas workers' compensation status, diabetes, history of ipsilateral shoulder surgery, and hypertension were negative predictors. [Orthopedics. 2021;44(3):e359-e366.].