OBJECTIVES: To compare persistence among patients with infusion (IV) vs. sub-cutaneous (SQ) biologic claims stratified by indication. METHODS: This retrospective, observational analysis used national data from Symphony Health Solutions (SHS). Adults with their first (index) IV or SQ biologic claim (excluding rituximab) from July 2, 2009 to January 8, 2010, were identified.  Proxy eligibility criteria included complete claims 180 days pre and 720 days post index.  Biologic claim clean period was 180 days pre-index.  SQ biologic users with reported days supplies that were <7 or >90 days were excluded. Duration of action for infusion products was based on package inserts.  Patients were censored after a gap of at least 90 days beyond the next expected re-fill interval. Results describe median time to discontinuation (Kaplan-Meier plots) covering 720 days. A Cox regression model assessed the IV vs SQ hazard ratio. RESULTS: