Comminuted proximal humerus fractures are more frequently being treated utilizing an intramedullary fibular strut allograft to assist with open reduction internal fixation. Although this technique has led to improved outcomes, avascular necrosis, rotator cuff failure, and/or prominent hardware may still occur necessitating conversion to reverse shoulder arthroplasty. The presence of an intramedullary strut allograft makes this conversion technically demanding and creates certain potential complications unique to this group. This manuscript details the conversion of a proximal humerus open reduction internal fixation with a fibular strut allograft to reverse shoulder arthroplasty including presurgical workup, surgical techniques, and pitfalls for undertaking this increasingly common scenario.