Gastroenterology Prior Authorization and Denial Guide

Prior authorization requirements for IBD biologics, step-therapy documentation, endoscopic procedure coverage and frequency rules, and appeal frameworks for GI denials, grounded in Aetna CPBs, UHC Coverage Determination Guidelines, Cigna Medical Coverage Policies, ASGE and ACG clinical guidelines, and USPSTF colorectal cancer screening recommendations.

Colonoscopy billing: colonoscopies performed for colorectal cancer screening under USPSTF guidelines are covered as preventive services without cost-sharing under the ACA for in-network providers. Diagnostic colonoscopies (with a known indication such as rectal bleeding or prior polyp history) are covered as diagnostic services and are subject to cost-sharing. The ACA requires that when a screening colonoscopy is converted to a diagnostic procedure (polyp removed, biopsy taken), the preventive service cost-sharing protection continues — several major payers have been required to update their billing practices on this issue under the ACA and HRSA guidance. EGD frequency rules apply at most payers: repeat upper endoscopy within 12 months requires documentation of a new indication.

IBD biologic therapy: adalimumab, infliximab, ustekinumab, vedolizumab, and risankizumab all require prior authorization for Crohn's disease and ulcerative colitis indications. Step therapy is required by most commercial payers — documentation of failure of conventional therapy (5-ASA for UC, immunomodulator for CD) prior to biologic initiation. Concomitant immunomodulator use requirements vary by agent and payer. Capsule endoscopy (CPT 91110) requires documentation of obscure GI bleeding or abnormal small bowel imaging — coverage for celiac disease follow-up varies by payer.