Aim: To estimate cost-savings from conversion to biosimilar pegfilgrastim-cbqv that could be reallocated to provide budget-neutral expanded access to AC (doxorubicin/cyclophosphamide) and TCH (docetaxel/carboplatin/trastuzumab) in breast cancer (BC) patients. Savings range from $5,413,016 to $32,478,097, respectively, in the 5000-patient HER2+ BC panel. Conversion to pegfilgrastim-cbqv could save up to $130 million and provide more than 220,000 additional cycles of antineoplastic treatment on a budget-neutral basis to BC patients.