Introduction: Repository corticotropin injection (RCI) has anti-inflammatory and immune-modulatory effects and is approved for multiple indications, including several rheumatologic conditions. The aims of this nationally representative, retrospective, observational study were to describe patient characteristics, RCI treatment patterns, and barriers to RCI use in patients with rheumatologic disease, and to compare medical resource use (MRU) before and after RCI therapy. Methods: A random sample of US physicians was recruited to abstract the medical records of deidentified patients with a diagnosis of rheumatoid arthritis (RA), psoriatic arthritis (PsA), dermatomyositis/polymyositis (DM/PM), or systemic lupus erythematosus (SLE) who had been treated with RCI in the previous 24 months. Patient characteristics and patterns of RCI use were identified. Mean MRU in the 3 months before and after RCI therapy was compared using paired-samples t tests.