CO-256: Service Not Payable Per Managed Care Contract

What Does CO-256 Mean?

CO-256 is a contractual adjustment indicating the managed care contract does not include payment for this service. The provider must either correct and resubmit (if the denial is due to a billing error), appeal (if the contract terms are being misapplied), or write off the amount (if the service is legitimately excluded). The patient cannot be billed for services denied under the managed care contract unless the contract explicitly permits balance billing.

CARC 256 fires when a managed care payer determines that the billed service is not payable according to the specific terms and conditions of the provider's managed care contract. This is a contract-level denial — the payer is not saying the service was not performed or not medically necessary in general, but that the contract between the provider and the payer does not include reimbursement for this particular service.

The reasons behind CARC 256 vary widely. The service may be explicitly excluded from the contract's covered services list, the provider may have failed to obtain a required prior authorization, the service may have been performed out-of-network under a plan that restricts network access, the patient may have exhausted benefit limits for this service type, or the claim may not comply with the contract's specific billing guidelines (modifiers, place of service codes, referral requirements).

CARC 256 appears with Group Code CO, making it a contractual write-off. The provider cannot bill the patient for services denied under the managed care contract unless the contract specifically permits balance billing for excluded services. The determination of whether to write off, resubmit, or appeal depends on the specific contract provision that triggered the denial.

Common Causes

How to Resolve

Review the managed care contract to understand why the service is not payable, then correct billing errors, obtain retroactive authorization, or write off the denied amount based on the specific contract terms.

1. Pull the contract Retrieve the managed care contract and locate the specific provision governing coverage for this service type. Check for exclusions, authorization requirements, benefit limits, and billing guidelines.
2. Determine if the denial is correctable Assess whether the denial resulted from a billing error (wrong modifier, missing referral), missing authorization, or exceeded benefit limit — versus a genuine service exclusion.
3. Correct and resubmit billing errors If the denial was caused by incorrect modifiers, place of service, or missing referral documentation, fix the claim and resubmit.
4. Seek retroactive authorization If prior authorization was required but not obtained, submit a retroactive authorization request with clinical documentation supporting medical necessity. If approved, resubmit the claim.
5. Appeal contract misapplication If the payer is misinterpreting the contract, file an appeal citing the specific contract language, medical necessity evidence, and clinical rationale for why the service should be covered.
6. Write off genuine exclusions If the service is clearly excluded from the contract, post the adjustment as a contractual write-off. Document the exclusion and flag it to prevent future claims for the same excluded service.

Common RARC Pairings

The RARC code tells you exactly what triggered the CO-256:

How to Prevent CO-256

• Review managed care contracts thoroughly to understand covered services, exclusions, authorization requirements, and billing guidelines before rendering services
• Verify patient eligibility and plan-specific coverage before scheduling services that may be excluded under their managed care plan
• Obtain all required prior authorizations before rendering services — maintain a payer-specific authorization requirement matrix
• Stay current with contract amendments and updates that may change coverage terms or billing requirements
• Train billing staff on contract-specific requirements for each managed care payer, including required modifiers and referral procedures
• Audit CO-256 denial patterns by payer to identify recurring contract compliance gaps and address them systematically

General Prevention

• Verify patient eligibility and plan-specific coverage details before scheduling services that may be excluded under their managed care plan
• Obtain all required prior authorizations before rendering services — track authorization requirements by payer and service type
• Stay current with managed care contract updates and amendments that may change coverage terms, billing requirements, or authorization procedures
• Train billing staff on contract-specific requirements for each managed care payer, including modifiers, referral requirements, and place of service rules
• Conduct regular audits of managed care denials to identify contract terms that are frequently triggering CO-256 and address systemic compliance gaps

Related Denial Codes