Therapeutic drug monitoring (TDM) has emerged as a means to optimize biologics and guide clinical decisions in inflammatory bowel disease (IBD). Golimumab (GOL) is a human monoclonal antibody to TNF-alpha approved for treatment of moderate-to-severe ulcerative colitis (UC). There is evidence to support TDM for other anti-TNFs but limited data is available for GOL. We present our experience in using TDM of GOL maintenance therapy in UC patients.