CO 297 denial code

Claim adjustment reason code 297. Often reported as CO 297 or OA 297.

Medical plan: bill the vision plan

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 297 means

Send this service to the patient's vision plan; the medical plan has no benefit for it and did not pass the claim along.

The medical payer considers this a vision service, such as a routine eye exam, glasses, or contact lenses. The claim was not forwarded, so you need to bill the vision plan yourself. Code 298 is the forwarded version.

Medical eye care for a diagnosed condition may still belong with medical, so check how the service was coded.

Group codes seen with 297

On a remittance, 297 comes after a group code. These are the ones it is most often reported with:

• CO 297 (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 297 (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

• A routine vision exam or eyewear was billed to the medical plan.
• The diagnosis on the claim pointed to routine vision rather than a medical eye condition.
• The plan carves vision benefits out to a separate vendor.

What to do next

1. Verify the patient's vision coverage and vendor.
2. Bill the vision plan with its required format and codes.
3. If the visit was medical, correct the diagnosis coding and resubmit to the medical plan.

Related codes

• 298 (reason code) Medical plan forwarded to vision plan