Background: Plerixafor, in combination with granulocyte colony-stimulating factor (G-CSF), is approved in the United States for mobi-lization of hematopoietic stem cells for collection before autologoustransplantation in patients with multiple myeloma (MM) and non-Hodgkin lymphoma (NHL). Health economic data on different stemcell mobilization regimens will aid decision making at bone marrowtransplant (BMT) centers. Objective: To develop a budget impact model that allows hospitaladministrators and transplant physicians in the United States to estimatethe clinical and budgetary impact of changes in mobilization regimens. Methods: The plerixafor model focuses on costs incurred by ahospital/transplant center over a 1-year period. A specific base caseis developed using data from individual hospitals/transplant centers,including first and remobilization regimens, duration of pre- andperi-apheresis (for both first and remobilization), percentage ofpatients meeting minimum CD34 + counts after first mobilization,and laboratory tests during peri-apheresis. A hypothetical base caseusing G-CSF + chemotherapy for first mobilization with plerixafor incombination with G-CSF for remobilization was compared with a sce-nario (currently practiced in many BMT centers) in which plerixaforin combination with G-CSF was used for first and repeat mobilization. Results: For 100 patients with MM or NHL, total plerixafor useincreased 90% and 68%, respectively, leading to a 2% increase in suc-cessful mobilizations (96.8% in the base case and 98.6% in the sce-nario) for MM and a 10% increase (87.1% in the base case and 95.9%in the scenario) for NHL. Remobilizations were reduced by 57% forMM and 68% for NHL. The annual budget decreased by 14% (-$2,073/patient) for MM and 6% (-$1,463/patient) for NHL; decreases in labo-ratory, pre- and peri-apheresis, storage (for NHL) and hospitalization(due to adverse events) costs offset increases in pharmacy costs. Healthresource utilization and salvage therapy were also reduced in the sce-nario. Total/postmobilization costs decreased for both MM (-$1,648/patient) and NHL (-$1,463/patient). Conclusions: The above scenario suggests that increased use ofplerixafor in patients with MM and NHL may not only result in bet-ter clinical outcomes (more successful first mobilizations with fewer remobilizations), but also may reduce costs of mobilization. The flex-ibility and scope of the plerixafor budget impact model allows indi-vidual BMT centers to estimate budgetary and clinical outcomes dueto changes to their mobilization protocol.