Total shoulder replacement (TSR) is an effective treatment of shoulder arthritis. However, subscapularis insufficiency after TSR remains a significant cause of poor outcomes after shoulder arthroplasty. We describe a novel technique for performing a TSR entirely through the rotator interval (RI) without tenotomy of the subscapularis or supraspinatus tendons and without dislocating the shoulder using the superior approach. We prospectively followed up 22 patients who underwent this procedure. Subjective patient satisfaction, Constant, Simple Shoulder Test (SST) scores, and range of motion (ROM) were evaluated preoperatively and postoperatively at a mean follow-up of 29 months. Radiographic findings are also presented. Subjective patient satisfaction results were good in 5 of 17 patients and excellent in 12. Patients also had significant increases in Constant, visual analog scale, SST, and ROM scores. One patient was excluded due to a traumatic periprosthetic fracture (fall), 3 patients refused to return for follow-up, and 1 patient was lost to follow-up. Postoperative results included nonanatomic humeral head osteotomies in 6, residual inferior humeral neck osteophytes in 8, and the humeral head prosthesis was undersized in 5. The patients had favorable clinical outcomes. This technique for TSR demonstrates that in the postoperative period, patients can immediately partake in unrestricted physical therapy. This study reports the clinical outcomes of this technique for TSR with a minimum of 2 years of follow-up. Level 4; Case series, treatment study.