835 Denial Combination
CO-97+N56
Contractual Obligation · Service-Line Level Adjustment
Coding ErrorWhat This Combination Means
This combination indicates the payer denied the service because an incorrect or invalid procedure code was submitted that is bundled into or already paid as part of another service. The RARC N56 specifies the coding error is invalid/incorrect, while CARC 97 confirms payment was already made through another code. The provider must write off the denied amount as a contractual adjustment.
Financial Responsibility
provider writeoff
Provider must absorb this amount as a contractual write-off and cannot balance bill the patient. The service was either already paid through a different code or the incorrect code submitted cannot be reimbursed separately.
N/A
Appeal Success
Immediate (write-off)
Avg. Resolution
Easy
Difficulty
No
Appealable
Step-by-Step Resolution
Steps tailored specifically to this CO-97+N56 combination — not generic advice.
- 1
Verify the procedure code submitted matches the service performed
Compare the denied code against documentation to identify if the wrong CPT/HCPCS code was billed or if it duplicates a service already paid
- 2
Check the remittance advice for the primary service that received payment
Review loop 2110 Service Payment Information REF segment to identify which procedure code already includes this benefit
- 3
Post the contractual adjustment as a write-off to the patient account
Apply CO-97 adjustment without transferring any balance to patient responsibility; update coding guidelines to prevent future incorrect code submissions for bundled services
Specialty Context
How CO-97+N56 typically presents across different practice types.
Dental
Common when separate billing for procedures included in comprehensive codes (e.g., billing prophylaxis and fluoride separately when already bundled, or using incorrect CDT code that duplicates coverage under another procedure)
Medical
Frequently occurs with surgical packages, E&M services bundled into procedures, lab panels, or modifier-51 multiple procedure scenarios where an incorrect code was used instead of the appropriate bundled or component code
Behavioral Health
May appear when billing individual therapy components using incorrect codes that are already covered under intensive outpatient program (IOP) or partial hospitalization program (PHP) codes, or when wrong CPT code submitted for covered service type
Individual Code References
View the standalone definition for each code in this combination.
Medicare Contractor Guidance for CARC 97
FCSO + NoridianThere are a few scenarios that exist for denial reason code CO 97. Please review the associated remittance advice remark code (RARC) noted on the remittance advice for your claim and then refer to the specific resources and tips to prevent the denial.
How to Prevent CARC 97 Denials
- ✓
RARC M15 (Bundled services): If the procedure code has a 'b' status on the Medicare Physician Fee Schedule (MPFS) database, the service should not be billed to Medicare. Check your most frequently billed procedure codes on the First Coast fee schedule lookup tool — if status is 'b', do not bill Medicare.
- ✓
RARC M144 (Pre/post-operative care): If billing for split care, coordinate split-care billing activities with other provider(s) involved in the patient's care, and ensure the surgical code is billed before the services for post-operative care are billed.
- ✓
RARC N70 (Consolidated billing): Before providing services to a Medicare beneficiary, determine if a home health episode exists. Ask the beneficiary if they are receiving home health services under a home health plan of care. Always check beneficiary eligibility prior to submitting your claim via SPOT.
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