OBJECTIVES: There is a dearth of published health economic evidence on stem cell (SC) mobilization that can be leveraged effectively for transplant center decision- making.  Our objective was to develop representative budget impact models (BIM) for key decision makers to estimate the total financial impact of adopting plerixafor for SC mobilization patients undergoing autologous peripheral stem cell transplantation (ASCT) for multiple myeloma and lymphoma. The BIMs were developed for EU5 (France, Germany, Italy, Spain, UK) and United States (US). METHODS: Prior to BIM development, in-depth interviews were conducted in EU5 (n=33) and US (n=20), to determine the most influential decision-maker(s) for choosing a mobilization regimen. The choice of inputs and outputs that are critical for the adoption of plerixafor at the hospital level, were determined. Additionally, the BIM was developed using inputs from published literature and market research. RESULTS: Primary research revealed that the center director and treating physician are the most influential decision makers, while hospital administrators, transplant coordinators, pharmacy directors, and apheresis directors have a more limited role. There was consensus on inputs critical for assessment: clinical (drug/regimen utilization, apheresis days, and success/failure rates) and economic (mobilization costs; drug costs; apheresis cost and hospitalization costs). Model outputs include: first mobilization success and total mobilization budget impact. Interviews with clinical experts, and primary literature review determined that the relevant mobilization regimen comparators for the models are Granulocyte-Colony Stimulating Factor (G-CSF) alone, G-CSF and plerixafor, G-CSF and chemotherapy mobilization with cyclophosphamide and the triple regimen G-CSF, chemotherapy mobilization and plerixafor. CONCLUSIONS: Conducting primary interviews with key stakeholders and using the latest clinical practice information for critical inputs/outputs is essential for developing a representative model that is applicable to decision-makers.