OBJECTIVES:  To describe real-world treatment patterns with anti-tumor necrosis factor (anti-TNF) therapy among patients with inflammatory bowel disease (IBD) in a large health plan. METHODS:  A retrospective cohort study was performed using the databases of Maccabi Healthcare Services (MHS), a 2-million-member non-profit-making health plan in Israel. The study population included MHS members diagnosed with ulcerative colitis (UC) or Crohn’s disease (CD), who initiated infliximab or adalimumab in 2010-2014 (index purchase). Treatment patterns in the first year were described, including discontinuation (defined as a treatment gap > 60 days), switching to a different biologic (also including golimumab, natalizumab and vedolizumab), dose escalation, and add-on therapy. RESULTS:  The study population included n=204 UC patients (mean age: 33.1 ±SD 15.1 years) and n=729 CD patients (32.3 ± 14.9 years). Mean time from diagnosis to anti-TNF initiation was 5.4 ±4.9 years. Over ninety percent of UC patients had prior experience with both 5-aminosalicylic acid (5-ASA) and corticosteroids (CS), compared to 63% of CD patients. Prior use of immunomodulators (IM) was comparable between the groups (approximately 80%). At 12 months from index purchase, 59% of patients persisted with their initial biologic therapy (of them, 10% had anti-TNF dose escalation), and 12% switched biologic. Add-on therapy was more frequent in UC (58%) patients compared to CD (44%). CONCLUSIONS:  The study results indicate that a substantial proportion of CD and UC patients discontinue or switch biologic within a year, suggesting suboptimal therapy and complex treatment pathways.