Background: Pegfilgrastim (pegfil) injection is indicated to decrease the incidence of infection, as manifested by febrile neutropenia, in patients with non-myeloid malignancies receiving myelosuppressive anti-cancer drugs associated with a clinically significant incidence of febrile neutropenia. Assuming biosimilarity of biosim-pegfil and pegfil in the prevention of febrile neutropenia, we estimated cost minimization of conversion from pegfil to biosim-pegfil and subsequent potential expanded access due to cost savings. Methods: A cost minimization model was conducted based on a hypothetical panel of 20,000 patients using average selling price (ASP) for one chemotherapy cycle. ASP was obtained from 1Q 2019 payment allowance limits. The simulation included two steps: 1) cost minimization was calculated per cycle (biosim-pegfil and pegfil is administered 1 dose per cycle) when patients were converted to biosim-pegfil from pegfil on ratio of 10% to 100% at 10% intervals and at a discount from 15% to 35% at 5% intervals, and 2) expanded access to biosim-pegfil was calculated based on budget neutrality. Since pegfil has two forms of availability (Neulasta and Neulasta-Onpro) with the same price, results were to either conversion scenario. Results: Per-cycle per-patient cost minimization from converting pegfil to biosim-pegfil ranged from $702.27 (15% discount) to $1,638.63 (35% discount). For 20,000 patients, this yields savings of over $14 million (15% discount) to $32 million (35% discount) at 100% conversion rate. When half the patients were converted to biosim-pegfil, savings could range from > $7 million (15% discount) to > $16 million (35% discount). With 100% conversion rate and 15% discount, 3,529 additional patients could be treated with the savings generated. At 50% conversion rate, cost savings could be applied to another 1,765 patients with 15% discount, 3,333 patients with 25% discount, and 5,385 patients with 35% discount, respectively. Conclusions: Conversion from pegfil to biosim-pegfil can lead to potential cost savings and these savings can be applied to offer increased access to supportive care with biosim-pegfil for patients receiving chemotherapy on a budget-neutral basis. For payers with larger populations, savings can be substantial. More studies are warranted to evaluate such potential cost savings due to use of biosim-pegfil over reference pegfil.