835 Denial Combination
CO-236+N104
Contractual Obligation · Service-Line Level Adjustment
Coding ErrorWhat This Combination Means
This combination indicates the claim was received by the wrong Medicare contractor or payer jurisdiction, and the NCCI/coding edit cited in CARC 236 may be a secondary reason or a jurisdictional coding rule that does not apply at this contractor. The N104 remark clarifies that the primary issue is jurisdictional rather than a coding incompatibility that requires correction, meaning the claim needs to be submitted to the correct payer or Medicare Administrative Contractor (MAC) for processing.
Financial Responsibility
provider writeoff
Provider must write off this amount as a contractual adjustment because the claim was processed (and denied) by the wrong payer jurisdiction. The amount cannot be billed to the patient under group code CO rules.
N/A
Appeal Success
7-14 days (re-routing to correct payer)
Avg. Resolution
Medium
Difficulty
No
Appealable
Step-by-Step Resolution
Steps tailored specifically to this CO-236+N104 combination — not generic advice.
- 1
Identify the correct Medicare contractor or payer jurisdiction
Use the CMS website (www.cms.gov) as specified in the RARC to determine which MAC or contractor has jurisdiction based on the service location, provider address, or beneficiary residence
- 2
Submit the claim to the correct payer jurisdiction
File as an original claim with the correct MAC or payer, ensuring all required documentation and supporting information is included for first-time processing
- 3
Write off the denied amount from the incorrect payer
Post the CO adjustment to close the balance with the wrong contractor; do not bill the patient per contractual obligation rules
Specialty Context
How CO-236+N104 typically presents across different practice types.
Dental
Medical
Common when provider submits Medicare claims to the wrong MAC jurisdiction (e.g., DME MAC vs. Part B MAC, or JE vs. JF contractor), particularly for multi-state practices or mobile service providers
Behavioral Health
May occur when behavioral health services are submitted to the wrong Medicare jurisdiction or when coordination between behavioral health carve-out plans and primary Medicare contractors is unclear
Individual Code References
View the standalone definition for each code in this combination.
Medicare Contractor Guidance for CARC 236
FCSO + uhc + aetna + bcbs_azThis procedure or procedure/modifier combination is not compatible with another procedure or procedure/modifier combination provided on the same day according to the National Correct Coding Initiative. This denial is received when the service(s) has/have already been paid as part of another service billed for the same date of service.
How to Prevent CARC 236 Denials
- ✓
If an NCCI associated modifier is clinically appropriate, apply the appropriate modifier to the minor/column 2 code only. Effective with date of service July 1, 2019, modifier 59 or subsets may be applied to either the major or minor code for Part B services only.
- ✓
Refer to the modifier policy indicator column in the PTP edit tables: 0=modifier not allowed, 1=modifier is allowed, 9=not applicable.
- ✓
Never append a modifier to solely bypass an NCCI PTP edit.
- ✓
Validate for the appropriate procedure/modifier combination via the Modifier lookup tool.
- ✓
Procedures are to be reported with the most comprehensive code.
- ✓
Stay up to date with the quarterly CMS updates on NCCI page.
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