In the recently published guidelines regarding the role of therapeutic drug monitoring (TDM) in inflammatory bowel disease (IBD), the American Gastroenterological Association (AGA) advocates reactive TDM in adults with active IBD failing response to anti-tumor necrosis factor (TNF) therapy.1 In contrast, no recommendation was made regarding proactive TDM of anti-TNFs for patients who have quiescent disease owing to a “knowledge gap.”1 We agree with the guidelines regarding reactive TDM, but disagree with the assertion that proactive TDM cannot be recommended owing to “limited data” and a potential “concern for harm.” Although there are more data on reactive versus proactive TDM, the quality of studies assessing both TDM strategies are based mainly on retrospective/exposure-association studies.