CMS 2026 Alert: Quarterly ICD-10-CM & NCCI updates active.
CO-231 - Denial Journal
CARC CO — Contractual Obligation

CO-231

Mutually exclusive procedures cannot be done in the same day/setting

What This Code Means

NCCI edits flagged two procedures billed together as clinically mutually exclusive.

Common Causes

  • Two procedures billed that logically can't both be performed in the same encounter
  • Modifier used to bypass an edit that shouldn't be bypassed

How to Resolve or Appeal

  1. Review the NCCI edit table for the specific code pair
  2. Bill only the appropriate procedure, or correct coding if one was billed in error

Educational reference only — not medical or legal advice. Always confirm code usage and appeal rights with the specific payer.

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