To estimate average, initial, and cumulative procedure related costs from a US payer perspective extending up to 3 years for the overactive bladder (OAB) interventions: sacral neuromodulation (SNM), intra-detrusor botulinum toxin A (BoNTA), and augmentation cystoplasty (AC) for antimuscarinic refractory patients. Costs (2007 US dollars) were calculated using Current Procedural Terminology (CPT) codes, Ambulatory Payment Classification (APC) codes; Diagnosis Related Group (DRG) payments, and Healthcare Common Procedure Coding System (HCPCS) Level II Codes extracted from the literature and from the SNM device manufacturer. CPT codes were converted to costs using the Center for Medicare and Medicaid Services (CMS) Relative Value Unit (RVU) fee schedule. Sensitivity analyses were performed to evaluate assumptions and uncertainty of results based on plausible variation in estimates of key cost drivers. The initial treatment cost was $22,226, $1,313, and $10,252 for SNM, intra-detrusor injection of BoNTA, and AC respectively. The first-year cost was $23,614, $2626, and $11,637 respectively. Three years after initiating treatment, the cumulative cost was $26,269, $7651, and $14,337 respectively. Sensitivity analyses revealed that SNM persisted as the most costly intervention in all scenarios. The 3-year cumulative cost range produced by the sensitivity analyses for SNM, BoNTA, and AC was $25,384-$27,357, $4586-$11,476, and $12,315-$16,830, respectively. All estimates of cost endpoints for SNM were greater than those for BoNTA and AC. These cost estimates, when combined with data on outcomes and risks, are important components of a robust health care technology assessment of antimuscarinic treatment failure options.