OBJECTIVES: Biologics such as etanercept, can be efficacious in reducing disease activity in their authorised indications, but are considered costly. The objective of this study was to assess future budget­-impact of introducing an etanercept biosimilar in the EU5 for all licensed adult indications. METHODS: A budget­-impact model (BIM) was developed to estimate the impact of potentially introducing an etanercept biosimilar on the healthcare budgets in over a five­-year horizon (2016-­2020) from the payer’s perspective. Prevalence­-based, incidence-­based and country­-specific model adaptations evaluate the impact of introducing an etanercept biosimilar to a segment of the anti­-TNFs market that includes innovator etanercept and adalimumab for rheumatoid arthritis (RA), psoriatic arthritis (PsA) psoriasis (PsO) and ankylosing spondylitis (AS); comparing total costs for scenarios with and without the biosimilar. Patients naïve to biologics, stable on, or failing the first biologic were tracked under a set of conservative assumptions: (1) uptake of 5% to 40% from etanercept to the biosimilar; (2) anti­-TNF price erosion of 5% per year; (3) unknown price of etanercept biosimilar – two discount scenarios versus etanercept (10%, 25%) were applied. RESULTS: The hypothetical introduction of an etanercept biosimilar in the biologic treatment setting for scenarios with a 10% or 25% cost reduction compared with innovator etanercept results in projected net budget­-savings of (millions): (1) UK €111–284, (2) France €35–81, (3) Germany €76–187, (4) Italy €46–111 and (5) Spain €28–65. Such savings, could be used to fund treatment for an additional 3,100 (UK) to 17,130 (Germany) patients with etanercept biosimilar over five­-years. CONCLUSIONS: The introduction of an etanercept biosimilar could represent substantial cost­-saving potential for EU5 healthcare systems; budget­-impact was sensitive to market uptake-­rates and discounts versus etanercept. These savings could be used to treat additional patients with a biosimilar.