CO 276 denial code

Claim adjustment reason code 276. Often reported as CO 276 or OA 276.

Prior payer denied, so not covered here

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 276 means

The service was denied by an earlier payer, and this payer will not cover it either because it follows the prior denial.

On a secondary or later claim, this code says the payer will not pay because the primary or another earlier payer denied the service. Many secondary plans only pay when the primary allowed the service.

Fixing the primary denial, if it can be fixed, is usually the path to getting the secondary paid too.

Group codes seen with 276

On a remittance, 276 comes after a group code. These are the ones it is most often reported with:

• CO 276 (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.
• OA 276 (Other Adjustment): Used for adjustments that are neither the provider's contractual write-off nor the patient's share. It often appears with coordination of benefits, for example when another payer already paid.

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 primary payer denied the service and the secondary plan follows that decision.
• The primary denial was for a correctable reason such as coding or authorization.
• The secondary plan does not pay services its primary did not allow.

What to do next

1. Review the primary remittance for the reason it denied the service.
2. Correct or appeal the primary denial if possible, then rebill the secondary with the new primary remittance.
3. If the primary denial stands, check the contracts and group codes before deciding who owns the balance.

Related codes

• 275 (reason code) Prior payer's patient share not covered
• 22 (reason code) Another payer may be primary
• 23 (reason code) Prior payer payment affected this claim