DENIAL CODE · CO-236

CO-236: Procedure/Modifier Combination Not Compatible

CO-236 means the payer says the procedure-and-modifier combination on this claim conflicts with another same-day code under NCCI rules, so it denied one of them.

Official (X12/WPC): "This procedure or procedure/modifier combination is not compatible with another procedure or procedure/modifier combination provided on the same day, per National Correct Coding Initiative or workers' compensation state regulations/fee schedule requirements."

Why payers issue CO-236

  • An NCCI edit flagged the code/modifier combination as incompatible
  • The wrong or unsupported modifier was used to bypass an edit
  • Two same-day services were coded as if inseparable
  • A documented exception to the edit wasn't shown

Is it recoverable? Recoverable when the services were distinct and the correct modifier applies — the appeal proves separateness against the specific NCCI edit.

How to appeal a Bundling / NCCI Edits denial →Recover a Bundling That Reduced Payment underpayment →

Common questions

What does CO-236 mean?

CO-236 means the payer says the procedure-and-modifier combination on this claim conflicts with another same-day code under NCCI rules, so it denied one of them. This procedure or procedure/modifier combination is not compatible with another procedure or procedure/modifier combination provided on the same day, per National Correct Coding Initiative or workers' compensation state regulations/fee schedule requirements.

How do I appeal or fix a CO-236 denial?

Recoverable when the services were distinct and the correct modifier applies — the appeal proves separateness against the specific NCCI edit. Common causes: an NCCI edit flagged the code/modifier combination as incompatible; the wrong or unsupported modifier was used to bypass an edit; two same-day services were coded as if inseparable; a documented exception to the edit wasn't shown.

Is a CO-236 denial worth appealing?

Recoverable when the services were distinct and the correct modifier applies — the appeal proves separateness against the specific NCCI edit. You only pay on what's actually recovered, so there's no cost to working the ones that are winnable.

Other denial codes
CO-197 · Precertification / Authorization Absent →CO-50 · Not Medically Necessary →CO-16 · Missing or Invalid Information →CO-45 · Charge Exceeds Fee Schedule →CO-97 · Bundled into Another Service →CO-29 · Timely Filing Expired →CO-96 · Non-Covered Charge →OA-18 · Duplicate Claim →OA-22 · Coordination of Benefits →CO-11 · Diagnosis Inconsistent with Procedure →CO-151 · Too Many Services (Frequency/MUE) →CO-B7 · Provider Not Eligible →CO-27 · Coverage Terminated →CO-204 · Not Covered Under Current Plan →CO-109 · Not Covered by This Payer →CO-119 · Benefit Maximum Reached →CO-4 · Modifier Inconsistent or Missing →CO-15 · Authorization Number Missing or Invalid →OA-23 · Prior Payer Adjudication Impact →CO-24 · Charges Covered Under Capitation →CO-26 · Expenses Incurred Prior to Coverage →CO-54 · Assistant Surgeon Not Covered →CO-55 · Experimental / Investigational →CO-58 · Inappropriate Place of Service →CO-59 · Multiple/Concurrent Procedure Reduction →CO-107 · Related/Qualifying Claim Not Identified →CO-167 · Diagnosis Not Covered →CO-170 · Denied for This Provider Type →CO-181 · Procedure Code Invalid on Date of Service →CO-182 · Procedure Modifier Invalid on Date of Service →CO-183 · Referring Provider Not Eligible to Refer →CO-185 · Rendering Provider Not Eligible →CO-198 · Precertification / Authorization Exceeded →CO-226 · Requested Provider Information Not Provided →CO-231 · Mutually Exclusive Procedures →CO-234 · Procedure Not Paid Separately →CO-242 · Out-of-Network / Non-Network Provider →CO-252 · Documentation Required to Adjudicate →CO-253 · Sequestration Reduction →CO-256 · Not Payable Per Managed-Care Contract →CO-288 · Referral Absent →CO-B15 · Qualifying Service Not Received →CO-B16 · New Patient Qualifications Not Met →CO-A1 · Claim/Service Denied (Remark Required) →

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