CO-236
CO · Contractual Obligation
CO-236 Denial Code: Procedure-and-modifier combination conflicts with NCCI edits
A procedure, or a procedure/modifier combination, billed together is not compatible under National Correct Coding Initiative (NCCI) edits or a state/workers'-comp policy. Closely related to CO-97 bundling.
- Group code
- CO - Contractual Obligation
- Code type
- CARC
- Billable to patient?
- No - contractual write-off
- Appealable?
- Sometimes - with the right modifier (if indicator 1)
- Category
- Bundling & NCCI Edits
- Common pairing
- M15
On a remittance
CAS*CO*236*125.00On a paper EOB it shows as CO-236.What CO-236 means
CO-236 means a procedure, or a procedure/modifier combination, conflicts with an NCCI procedure-to-procedure edit (or a workers' comp / state policy). One code is a component of the other, or the combination cannot be reported together as billed. If a distinct, separately identifiable service is documented, an NCCI-associated modifier may resolve it.
Common causes
- An NCCI PTP edit prohibits reporting the two procedures together as billed.
- One code is a component of a more comprehensive code.
- A workers' comp or state-specific policy bars the combination.
How to fix it
- Identify the conflicting code pair and check the NCCI modifier indicator.
- If documentation supports a distinct service, append modifier 59 or an X{EPSU} modifier and resubmit.
- If the edit is correct and no modifier is supported, write off the component line.
How to prevent it
- Scrub claims against current NCCI PTP edits before submission.
- Document distinct services clearly when reporting edit pairs with a modifier.
- Avoid unbundling unless documentation supports it.
Sometimes - with the right modifier (if indicator 1)Appealable when documentation supports a separate, distinct service and the NCCI edit allows a modifier override (modifier indicator 1).
Linked CMS edit: NCCI PTPDriven by National Correct Coding Initiative Procedure-to-Procedure edits. Check the edit pair's modifier indicator (0 = no override; 1 = a modifier may override when documentation supports a distinct service).
Appeal letter template
Fill in the bracketed fields, attach your supporting documentation, and send through the payer's appeal channel. This is a starting point — adjust to your payer's requirements.
Re: Appeal of NCCI Bundling Denial (CO-236) - Claim [Claim Number] Patient: [Patient Name] | Member ID: [Member ID] Date(s) of Service: [DOS] | Codes at issue: [CPT A] and [CPT B] To Whom It May Concern: CPT [CPT B] was denied under CO-236 as incompatible with CPT [CPT A]. These were separate and distinct services: [describe - different site/session/encounter]. Modifier [59 / XS / XE / XP / XU] is supported by the enclosed documentation. [Confirm the NCCI edit for this pair carries a modifier indicator of 1 (override allowed) before submitting.] We request that CPT [CPT B] be reprocessed and paid as a distinct procedural service. Documentation is enclosed. Sincerely, [Your Name], [Practice Name] | [Phone] | [NPI/TIN]