Background: Biosimilars are clinically equivalent and highly similar to brand yet cost significantly less. Financial savings are shared by patients, practices and payers, ranging anywhere from 21-24% based on 10/01/20 ASP data from CMS. The effective conversion to biosimilar products is vitally important to total cost-of-care savings and can be achieved without negatively affecting patient outcomes. Physician understanding and confidence in biosimilar products is seen as a major conversion barrier. Methods: Interchangeability is an FDA designation that allows generic drugs to be substituted for reference drugs at the pharmacy, without a physician’s consent. Currently no biosimilar has that FDA approval for interchangeability. Building on previous pharmacy auto-substitution processes with therapeutic interchange, a formalized biosimilar policy and SOP was developed to automate conversion from the reference biologic product to the P&T/Physician approved biosimilar. Workflow changes were instituted to alleviate the provider burden of patient-by-patient decisions and placed them with the pharmacy review team. Full staff support and understanding on biosimilar usage was endorsed through mandatory biosimilar education of physicians, advanced practice providers, pharmacists, nurses, financial navigators and prior authorization team members and tracked using meeting attendance and the online E-learning system. Patient education was verified using established teaching visits by tracking documentation in the electronic health record (EHR). Quantitative metrics and reports were developed to assist in tracking the number of unique patients receiving the brand or biosimilar agents. Billed product units per month were also tracked to facilitate auditing and assure accuracy. Baseline brand/biosimilar utilization data for Rituximab, Trastuzumab, and Bevacizumab was collected from July 1, 2019 through December 31, 2020. Results: During the baseline period of 7/01/19 – 12/31/19, biosimilar conversion ranged from 0% (trastuzumab) to 8.4% (rituximab). Following full staff education and physician consent, systematic auto-conversion to biosimilar products was initiated on January 1, 2020. Conversion rates based upon billed biosimilar units likewise improved from 11.7% (baseline) to 90.2% (2021 Q1) for rituximab, 8.4% to 87.4% for trastuzumab, and 0% to 90.0% for bevacizumab. Conclusions: Rapid and near-complete conversion from brand product to FDA approved biosimilar is feasible, measurable and can be scaled.