Introduction: There remains little evidence on rehabilitation protocols for proximal humerus fractures (PHFs), although early mobilisation has been associated with positive clinical outcomes. There may be a potential role in allowing patients with more stable fractures to undergo an accelerated rehabilitation process to facilitate quicker return to function, although it must be balanced with safety concerns of premature mobilisation and logistical concerns of implementation with excessive stratification. The study aim was to report the overall safety and outcomes of a simple and implementable 2-tier stratified rehabilitation protocol based on fracture stability adopted by our institution for nonoperatively treated PHFs. Materials and methods: Patients in our institution (level 1 trauma centre) with non-operatively treated PHFs underwent a stratified rehabilitation protocol that classified patients into Accelerated versus Standard arms - with more stable fractures undergoing an accelerated rehabilitation programme. The Oxford Shoulder Score (OSS), Quick Disabilities of the Arm, Shoulder and Hand Score (QuickDASH), EuroQol-5-Dimensions (EQ5D) questionnaires, shoulder range of motion (ROM) and grip strength were measured at six months and one year postinjury. The frequency of adverse events requiring surgical intervention was noted. Results: We included 164 patients and 43% (71/164) went through the accelerated protocol. Overall, patients had favourable OSS (median[range] 47[44-48]), EQ5D (median [range] 1.0[0.82-1.00]), QuickDASH scores (median[range] 2.3[0- 10.7]), and shoulder ROM and grip strength above the requirement for functional activities of daily living at 1 year. There were no adverse events reported 1-year post-injury. Conclusion: This study was the first to report the safety and outcomes of a stratified rehabilitation protocol for PHFs. Our simple 2-tier stratified rehabilitation protocol which allowed a shorter period of rehabilitation and earlier return to function for patients with more stable PHFs is implementable, safe and had overall favourable functional outcome scores.