BACKGROUND: Tofacitinib is an oral small molecule Janus kinase inhibitor for the treatment of ulcerative colitis (UC). AIMS: To evaluate real-world data in US patients with UC receiving tofacitinib. METHODS: Characteristics and outcomes of patients with UC initiating tofacitinib between 2018 and 2019 were assessed using data from the IBM(R) MarketScan(R) claims database. The index date was the first tofacitinib claim; pre- and post-index periods were 12 months. Outcomes included tofacitinib adherence/persistence, oral corticosteroid (OCS) use, and healthcare resource utilization (HCRU) and costs. RESULTS: Of 276 patients with UC who initiated tofacitinib, 68 (24.6%) were bio-naive, and 208 (75.4%) bio-experienced. At month 12, overall median tofacitinib adherence (proportion of days covered) was 0.82 (mean 0.68); 43.8% of patients discontinued tofacitinib (90-day gap). Of patients receiving OCS during the post-index 16-week tapering period, 40.4% discontinued OCS up to 12 months post-index. OCS use decreased in patients continuing tofacitinib versus those discontinuing tofacitinib (29.7% vs 59.5%, respectively). Reductions in all-cause and UC-related outpatient visits were observed for bio-naive (- 1.34 and - 0.88, respectively) and bio-experienced (- 4.72 and - 5.16, respectively) patients, post-index. Decreased UC-related costs per year were observed for bio-experienced patients (difference in post-index vs pre-index, - US$12,448; driven by changes in pharmacy costs), but not for bio-naive patients (US$47,152). CONCLUSIONS: In this real-world analysis in a mostly bio-experienced population, the majority of US patients with UC initiating tofacitinib remained on therapy at 12 months, and OCS use was reduced with tofacitinib treatment. HCRU (all patients) and UC-related costs were reduced in bio-experienced patients. The majority of patients with ulcerative colitis starting tofacitinib in this real-world study continued therapy at 12 months; there was a reduction in the use of steroids, and a decrease in healthcare resournce utilization and costs.