Prior Authorization for Sacral Nerve Stimulation in the Era of WISeR: Evaluation of U.S. Payer Coverage Policies

INTRODUCTION: Sacral nerve stimulation (SNS) is an established therapy for refractory urinary incontinence, yet the 2025 Wasteful and Inappropriate Service Reduction Model (WISeR) designated it as requiring mandatory prior authorization. No analysis has examined how U.S. payers translate SNS evidence into coverage policies or whether restrictions are evidence-based. We sought to: (1) compare covered and excluded indications, (2) evaluate restriction criteria and conservative therapy requirements, and (3) assess quality of evidence cited. METHODS: This was a systematic, retrospective analysis of publicly available SNS coverage policies. Independent reviewers extracted data from 11 major U.S. payers, including Medicare. Data included indications, contraindications, implantation criteria, and cited references. References were classified using Oxford Centre for Evidence-Based Medicine hierarchy into Levels I-V or "Other" (guidelines, technology assessments, regulatory documents). RESULTS: All payers covered core urinary indications, while 63.6% excluded neurologic disease. All required conservative therapy failure for trial, but specificity varied from specific drug combinations to voiding diaries. All required symptomatic improvement for permanent implantation; 90.9% specified > 50% improvement. References ranged from N = 15-112 per policy. While 90.9% cited Level I evidence, proportions ranged from 0% to 31.6%. Five payers had > 50% of references classified as "Other;" only Medicare had majority primary evidence (89.5%). DISCUSSION: While payers agree on core urinary indications, coverage for neurologic conditions is inconsistently defined. Because FDA labeling does not endorse SNS for neurologic etiologies such as spinal cord injury, variable exclusions are understandable yet create confusion for clinicians navigating prior authorization. Wide variation in therapy and documentation requirements highlights lack of transparency as WISeR expands. LEVEL OF EVIDENCE: Level III. LEVEL OF EVIDENCE: Level IV.