OBJECTIVES: A budget impact analysis was conducted to estimate the impact of Oralair® on a market of selected number of relevant grass allergens. METHODS: In this analysis the hypothetical market for grass allergens consisted of those compounds for which efficacy data of comparable high-quality evidence have been published. These compounds were Oralair®, Grazax® and ALK Depot SQ®. Actual German market data from 2008-2010 served as a basis for future estimates of market share development. Future predictions were made on market uptake and market dynamics (i.e. which drug increases their market share at the expense of another drug). German drug acquisition costs were taken from the Lauer-Taxe; average annual treatment related costs have been extracted from a supportive cost-effectiveness analysis. The analysis perspective was that of the German Statutory Health insurance (SHI). Three scenario analyses were conducted over a 5-year time horizon. RESULTS: The total market budget in 2010 for these 3 therapies was estimated at €48,209,211. The budget decreased with €7,049,756 over a 5-year period in the first scenario, when the annual uptake of Oralair® was set at +5% with market dynamics of 10%/90% (Grazax®/ ALK Depot SQ®). These savings represent 2.9% of the total cumulative reference budget varying from 1.0% in 2011 to 4.8% in 2015. In the second scenario market uptake for Oralair® was varied from +2% to +6% annually. Accordingly, the budget was reduced by €2,819,902 to €8,549,707. In the final scenario, shifting market dynamics from 0%/100% to 20%/80% (Grazax®/ ALK Depot SQ®) showed a reduction of €5,389,170 to €8,710,342. CONCLUSIONS: In all scenarios, an increase of Oralair’s® market share at the expense of Grazax® and ALK Depot SQ® was estimated to result in a decrease of the budget varying from €2,819,902 to €8,710,342 over 5 years. This results in Oralair® being a budget-saving treatment option.