Prescription drug costs exert profound effects on commercial insurance coverage and access to effective therapy. We aimed to assess threshold pricing to achieve budget neutrality of FDA-approved drugs treating irritable bowel syndrome from an insurance perspective, based on cost-savings resulting in decreased healthcare utilization through effective disease management. We constructed a decision-analytic model from an insurance perspective to assess the budget impact of IBS prescription drugs under usual insurance coverage levels in practice: (1) unrestricted drug access or (2) step therapy in a primary care population of middle-age, care-seeking IBS patients. Budget-neutral drug prices were then calculated which resulted in $0 budget impact to insurers with a short-term, one-year time horizon. If used according to FDA labeling, IBS-D drugs cost between $4778 and $16,844 per year and IBS-C drugs cost between $4319 and $4955 per year. These drug costs often exceed insurance expenditures of $6999 for IBS-D and $3929 for IBS-C if left untreated. Therefore, for drugs to have $0 budget impact to insurers, their prices would need to be discounted 36.7-74.2% for IBS-D drugs and 59.3-82.5% for IBS-C. IBS drugs are already priced to support step therapy "failing one of several common, inexpensive IBS treatments with a responder rate > 30-40%," reflecting the subpopulation with more severe disease and greater healthcare costs. Broader prescription drug coverage for patients failing common, inexpensive IBS treatments to which at least 30-40% of patients would typically respond appears warranted to enable gastroenterologists to offer personalized approaches targeting specific mechanisms of this heterogeneous disease.