Objective: To evaluate corticosteroid (CS)-related quality of care indicators in patients with ulcerative colitis (UC) and Crohn's disease (CD) in the US. Methods: Adults diagnosed with UC or CD and prescription fills for an oral CS were identified from a large commercial US claims database (2005-2013). Quality indicators included prolonged CS use (>= 60 days), use of CS-sparing therapy, and bone loss assessment. State-level variations in quality of care indicators were estimated using logistic regression models adjusting for age, gender, insurance plan type, and CD severity. Results: Of the 25,063 UC and 22,155 CD patients receiving CS, 16.1% and 12.6%, respectively, were prolonged CS users. Among prolonged CS users, 52.5% of UC and 68.2% of CD patients used CS-sparing therapy. Bone loss assessment was observed in 11.0% of UC patients with prolonged CS use and 7.7% of newly diagnosed CD patients. Prolonged CS use was the lowest in Kentucky (odds ratio [OR] = 0.59) and the highest in Wisconsin (OR = 1.41) for UC patients; the lowest in North Carolina and New York (both OR = 0.71) and the highest in Utah (OR = 2.42) for CD patients. CS-sparing therapy use was the lowest in Delaware (OR = 0.42) and the highest in Michigan (OR = 0.83) for UC patients; it was significantly different only in South Carolina (OR = 0.57) for CD patients. Bone loss assessment rates were the highest in Arizona (OR = 1.83) for UC patients and were the lowest in Mississippi (OR = 0.52) and the highest in Texas (OR = 1.51) for CD patients. Limitations: Information on disease severity was not available in the database. Conclusions: Significant regional variations in all three quality indicators were observed across the US.