How do I resolve a CO-236 denial?

Identify the conflicting code pair by checking the NCCI Mutually Exclusive (ME) edit table at cms.gov for the specific CPT codes billed. Determine if the service was genuinely two separate procedures — if so, a modifier may allow payment. If Modifier 59/XE/XS/XP/XU is clinically appropriate, add the modifier to the correct code and resubmit with clinical notes. If the services cannot be unbundled, remove the component code and write off the amount — do not bill the patient. Review your chargemaster or fee schedule to identify other commonly billed code pairs that trigger NCCI ME edits.

Can I appeal a CO-236 denial?

Yes. CO-236 denials are typically appealable with a 40% success rate. Resolution difficulty is Medium and typically takes 14-21 days.

835 Denial Combination

CO-236

Contractual Obligation · Service-Line Level Adjustment

What This Combination Means

This procedure or service is not payable when billed with another procedure or service performed on the same day — a mutually exclusive edit. The combination of codes billed is clinically illogical or administratively prohibited (NCCI or payer-specific edit). One of the two codes must be removed or modified.

40%

Appeal Success

14-21 days

Avg. Resolution

Medium

Difficulty

Yes

Appealable

Step-by-Step Resolution

Steps tailored specifically to this CO-236 combination — not generic advice.

1
Identify the conflicting code pair by checking the NCCI Mutually Exclusive (ME) edit table at cms.gov for the specific CPT codes billed.
2
Determine if the service was genuinely two separate procedures — if so, a modifier may allow payment.
3
If Modifier 59/XE/XS/XP/XU is clinically appropriate, add the modifier to the correct code and resubmit with clinical notes.
4
If the services cannot be unbundled, remove the component code and write off the amount — do not bill the patient.
5
Review your chargemaster or fee schedule to identify other commonly billed code pairs that trigger NCCI ME edits.

Specialty Context

How CO-236 typically presents across different practice types.

Dental

Common when a procedure and its component part are both billed (e.g., a crown and a buildup on the same tooth — some payers bundle the buildup into the crown code).

Medical

NCCI mutually exclusive edits prohibit certain CPT pairs that cannot reasonably be performed together. The NCCI table specifies which combinations are disallowed and whether a modifier can bypass the edit.

Behavioral Health

Rare in behavioral health. May appear when two therapy codes are billed that represent overlapping or identical time periods.

Individual Code References

View the standalone definition for each code in this combination.

CARC 236

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