Proximal humerus fractures are a common fragility fracture in older adults. A variety of treatment options exist, yet longer term outcomes of newer surgical treatments have not been extensively researched. Additionally, intermediate term outcomes following both surgical and non-surgical initial treatment of these injuries have not been evaluated at a population level. The purpose of this study was to utilise administrative data from Ontario, Canada to evaluate intermediate term outcomes following initial treatment of proximal humerus fractures. We used data from the Canadian Institute for Health Information to identify all patients aged 50 and older who presented to an ambulatory care facility with a “main diagnosis” of proximal humerus fracture from April 1, 2004 to March 31, 2013. Intervention codes from the Discharge Abstract Database were used to categorise patients into fixation, replacement, reduction or non-surgically treated groups. We used intervention codes to identify instances of complication-related operations following initial treatment (including fixation, replacement, hardware removal, rotator cuff repair and irrigation and debridement [I&D]) at one year post initial treatment. The majority of patients (28,369, 86.6%, 95% confidence interval [95% CI] 86.2–87.0%) were initially treated non-surgically, while 2835 (8.7%, 95% CI 8.4–9.0%) underwent initial fixation, 1280 (3.9%, 95% CI 3.7–4.1%) received primary joint replacement, and 276 (0.8%, 95% CI 0.8–1.0%) were initially treated with a reduction procedure. In the year following the initial treatment period, 127 (0.4%, 95%CI 0.4–0.5%) non-surgically treated patients underwent a replacement surgery, 292 (1.0%, 95%CI 0.9–1.2%) underwent fixation, and 12 (0.04%, 95% CI 0.02–0.07%) underwent a reduction procedure. Of the 2835 patients who received initial fixation, 57 (2.0%, 95% CI 1.6–2.6%) returned for a shoulder replacement, 80 received secondary fixation (2.8%, 95% CI 2.3–3.5%), 57 (2.0%, 95%CI 1.6–2.6%) underwent rotator cuff repair, 300 (10.6%, 95% CI 9.5–11.8%) had their implants removed, and 16 (0.6%, 95% CI 0.4–0.9%) returned for I&D. Of the 1280 patients who underwent initial replacement surgeries, 30 (2.3%, 95% CI 1.7–3.3%) returned for a secondary replacement, nine (0.7%, 95% CI 0.4–1.3%) underwent rotator cuff repair, and seven (0.6%, 95% CI 0.3–1.1%) had their implant removed. In the group who received initial reduction, eight (2.9%, 95% CI 1.5–5.6%) underwent a fixation procedure, six (2.2%, 95% CI 1.0–4.7%) received replacement surgeries, and five (1.8%, 95% CI 0.8–4.2%) each received rotator cuff repair and I&D in the year following initial treatment. The majority of proximal humerus fractures in patients 50 and older in Ontario, Canada are treated non-surgically. Complication-related operations in the year following initial non-operative treatment are relatively low. The most commonly observed procedure following initial fixation surgery is hardware removal.