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CO-299 Denial Code: Billing Provider Can't Be Paid

CO-299 means the payer determined the billing provider, the entity in box 33 that would receive payment, is not eligible to be paid for the service billed. It usually points to enrollment, credentialing, or billing-entity setup rather than the care itself.

Quick facts

Code
CO-299 (CARC 299)
Status
Active In use since July 1, 2019.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The usual group. The provider is responsible; the patient can't be billed while the enrollment or billing issue is resolved.
Official description
The billing provider is not eligible to receive payment for the service billed.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-299 means

CARC 299 says the billing provider is not eligible to receive payment for the service billed. Every claim identifies a billing provider in box 33 (name, address, and NPI in 33a) and a federal tax ID in box 25. The payer checks that entity against its enrollment records. If the billing entity isn’t enrolled, isn’t enrolled for that service or location, or isn’t allowed to receive payment for that service type, the claim is denied with CO-299.

This is different from CO-185, which concerns the individual who performed the service. With CO-299, the clinician may be fully credentialed, but the organization collecting the money isn’t set up to be paid.

Example: a practice opens a second location under a new group NPI. Clinicians are credentialed individually, but the new group NPI isn’t linked to the payer contract yet. Claims billed under it return CO-299.

Common causes

  • Group NPI or TIN not enrolled with the payer, or not linked to the contract.
  • New entity after a merger, acquisition, or tax ID change.
  • Location not enrolled, so the billing address in box 33 doesn’t match an approved site.
  • Service type outside the entity’s enrollment, for example a supplier billing a service it isn’t enrolled to furnish.
  • NPI and TIN mismatch between boxes 25 and 33a.
  • Enrollment terminated or lapsed, such as after missed revalidation.

How to fix it

  1. Check payer enrollment for the billing NPI, TIN, and location, including effective and end dates.
  2. Compare boxes 25, 33, and 33a to what the payer has on file.
  3. If the claim data was wrong, correct it and send a corrected claim with resubmission code 7 in box 22.
  4. If enrollment is missing or lapsed, complete or reinstate it and ask whether the effective date can cover past dates of service.
  5. Request reprocessing once enrollment is active.
  6. Watch timely filing while enrollment is pending; see CO-29.

How to prevent it

  • Enroll new entities and locations before billing under them.
  • Track revalidation dates for each payer.
  • Keep NPPES, payer records, and your billing system aligned. See provider enrollment denials.
  • Validate billing provider data before submission. A Claims Validator can catch NPI and TIN mismatches.

Specialty notes

Behavioral health groups that add new clinics, DME suppliers with location-specific enrollment, and practices going through ownership changes run into CO-299 most often.

Remark codes that may appear with CO-299

  • N761 (This provider is not authorized to receive payment for the service(s).): This provider is not authorized to receive payment for the services.
  • N760 (This facility is not authorized to receive payment for the service(s).): This facility is not authorized to receive payment for the services.
  • N257 (Missing/incomplete/invalid billing provider/supplier primary identifier.): The billing provider's primary identifier is missing, incomplete, or invalid.
  • N255 (Missing/incomplete/invalid billing provider taxonomy.): The billing provider's taxonomy is missing or invalid.
  • CO-185 (The rendering provider is not eligible to perform the service billed.): The rendering provider, rather than the billing provider, isn't eligible to perform the service.
  • CO-B7 (This provider was not certified/eligible to be paid for this procedure/service on this date of service.): The provider wasn't certified or eligible to be paid for the service on that date.
  • CO-170 (Payment is denied when performed/billed by this type of provider.): Payment denied when performed or billed by this type of provider.
  • CO-208 (National Provider Identifier - Not matched.): The NPI doesn't match the payer's records.

CO-299 FAQ

What's the difference between the billing and rendering provider?

The rendering provider (box 24J) performed the service. The billing provider (box 33 and 33a) is the entity that submits the claim and receives payment, often a group practice or facility. CO-299 is about the billing entity.

What typically causes CO-299?

A group NPI or tax ID not enrolled with the payer, enrollment that doesn't include the service or location, a new entity after an ownership change, or a billing NPI that doesn't match the TIN on file.

Can I resubmit under a different billing NPI?

Only if that entity actually furnished or is entitled to bill for the service and is enrolled with the payer. Billing under another entity just to get paid can create compliance problems.

Can a retroactive enrollment date fix CO-299?

Sometimes. Some payers grant enrollment effective dates that cover past services. Ask when you enroll, then request reprocessing of affected claims.