CPT code 49999 is an unlisted procedure code for operations involving the peritoneum and omentum when no specific CPT descriptor applies. As an unlisted abdominal surgery code, 49999 matters nationally because it is a catch‑all for atypical or novel procedures and for interventions that lack a direct CPT match. Use of an unlisted code typically requires additional documentation to justify the procedure performed and support coverage and payment decisions.

Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare and Medicare. Readers will find an overview of the code’s clinical scope, guidance on common documentation expectations, and the types of benchmarks and policy issues that commonly affect unlisted surgical codes. The content highlights where payers and Medicare commonly focus — clinical necessity, operative reports, and comparability to listed CPT codes — and outlines what information is typically reviewed during claims adjudication.

This publication provides clinicians and coding professionals with context about when 49999 is applied, the typical surgical settings for such procedures, and the operational considerations for national payers. Data not available in the input will be noted where relevant.