Objectives: Disagreement exists within the current literature as to whether performing an arthroscopic vs. open subpectoral bicep tenodesis with concomitant arthroscopic rotator cuff repair (ARCR) leads to significantly different outcomes. Therefore, the objective of this study is to use a matched cohort of patients who undergo arthroscopic versus subpectoral biceps repair with concomitant ARCR and assess if there is a significant difference in (Patient-Reported Outcomes Measurement Information System) PROMIS outcomes and the ability to achieve a minimal clinically important difference (MCID). Methods: Data from the electronic medical record, including operative reports, were retrospectively collected for patients who underwent ARCR performed by one of six fellowship-trained board-certified orthopedic surgeons at a single institution. Current Procedural Terminology (CPT) for open or arthroscopic biceps tenodesis with concomitant arthroscopic rotator cuff repair was used to identify patients who underwent this procedure concomitant with ARCR between 01/01/2016 to 12/31/2019.Preoperative PROMIS physical function (PF), pain interference (PI), and depression (Dep) scores were obtained at the closest date prior to arthroscopic rotator cuff repair, and postoperative scores were collected at every clinical visit thereafter. The final PROMIS score used for data analysis was determined by the patients’ PROMIS scores between 90 and 180 days. A delta PROMIS value was determined by taking the difference between the final PROMIS score and the preoperative score. Unadjusted bivariate analysis was performed to assess the differences in PROMIS outcomes between the two cohorts. The MCID was determined as one-half of the standard deviation of a given PROMIS value, which is consistent with the current orthopedic literature. Results: A total of 297 patients were identified underwent rotator cuff repair with concomitant biceps tenodesis. A total of 151 subjects underwent arthroscopic biceps tenodesis with concomitant ARCR, while 147 underwent open subpectoral bicep tenodesis. The average time to follow up was 132.2 days for the arthroscopic cohort and 136.3 days for the subpectoral open group.Bivariate analysis demonstrated no significant difference between the two cohorts for insurance, race, ethnicity, last PROMIS input day, mechanism of injury, ASA class, or Charleston Comorbidity Index (CCI). There was a significant difference for patients who required contaminant subscapularis repair (p < 0.001) and revision surgery (p < 0.001).Unadjusted t-test analysis showed that patients in the arthroscopic biceps tenodesis cohort had significantly higher postoperative PROMIS PF and lower PROMIS PI and Dep scores. (P = 0.001, P = 0.001, and P = 0.007, respectively) when compared to their preoperative PROMIS values. The subpectoral open biceps tenodesis cohort did not show a significant difference in the postoperative PROMIS Dep score when compared to its preoperative score (P = 0.18), but it did show a significant improvement for postoperative PROMIS PF and PI (P = 0.001 and P = 0.04, respectively). No significant difference was determined between the arthroscopic bicep and subpectoral bicep tenodesis cohorts for delta PROMIS PF, PI, and Dep (P = 0.50, P = 0.51, and P = 0.10, respectively). A chi-square analysis found no significant difference between the achievement of MCID for PROMIS PF, PI, and Dep (P = 0.64, P = 0.72, and P = 0.95, respectively). Finally, no significant difference was determined between the time it took to achieve a minimal clinically important difference for PROMIS PF, PI, or Dep for patients who underwent arthroscopic rotator cuff repair with concomitant arthroscopic biceps tenodesis when compared to subpectoral open biceps tenodesis. Conclusions: The objective of this study was to assess differences in PROMIS outcomes for patients who undergo ARCR with concomitant arthroscopic or open subpectoral bicep tenodesis. The main findings of our study highlighted that patients with arthroscopic biceps tenodesis showed significant improvement at six months for PROMIS PF, PI, and Dep, whereas those who underwent an open subpectoral approach showed significant improvement in PF and PI but not Dep. Our findings suggest there may be a slight benefit for patients who undergo arthroscopic tenodesis when compared a subpectoral open approach. However, no significant differences were found between the two cohorts for PROMIS or the time to reach MCID. Therefore, suggesting the modality of bicep tenodesis with concomitant ARCR does not impact patient outcomes at 6-month follow-up. [Table: see text][Table: see text][Table: see text]