CO 299 denial code

Claim adjustment reason code 299. Often reported as CO 299.

Billing provider cannot be paid for this

Unofficial reference. This is our own plain-English explanation, not the official code text. Payer rules differ. Verify with the payer and the official X12 code list. AlphaPrefix is not affiliated with X12, CMS or any payer. Data last updated Nov 11, 2026.

What 299 means

The billing provider on the claim is not eligible to receive payment for the service billed.

The payer is saying the entity in the billing provider field cannot be paid for this service, even if the service itself is covered. It can be an enrollment, provider type, or setup problem.

Look at which provider was billed and whether a different billing entity, such as a group or facility, should have billed instead.

Group codes seen with 299

On a remittance, 299 comes after a group code. These are the ones it is most often reported with:

• CO 299 (Contractual Obligation): The provider's side of the ledger. The reduction comes from the payer contract or a rule the provider has to follow, and the patient normally cannot be billed for it.

The payer chooses the group code for each adjustment, so the same reason code can appear with another group code on your remittance. Read the two together. More about group codes.

Common causes

• The billing provider is not enrolled or credentialed for that service with the payer.
• The provider type is not allowed to bill that service under the payer's rules.
• The wrong billing NPI or tax ID was used on the claim.

What to do next

1. Check the billing provider's enrollment and the services it is allowed to bill.
2. Correct the billing provider details and send a corrected claim if they were wrong.
3. Contact provider enrollment to fix credentialing gaps before rebilling.

Related codes

• 16 (reason code) Missing information or billing error
• 283 (reason code) Attending provider cannot direct care