This project will examine how reimbursement incentives contribute to prescribing patterns. Using a regression discontinuity design, the project will compare the rate of administration of biosimilars between 340B and non-340B hospitals before and after the 2018 Medicare reimbursement changes created stronger incentives for 340B providers to administer biosimilars relative to non-340B providers. It also will determine if this impacted adoption of new biosimilars. The study will use the Medicare 20% sample of fee-for-service outpatient claims data and the Beneficiary Summary File, the Hospital Cost Report Information System (HCRIS) database, and the 340B Information System for data on 340B hospital participants.