OA 298 denial code

Claim adjustment reason code 298. Often reported as OA 298 or CO 298.

Medical plan forwarded to 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 298 means

The medical plan found no benefit for the service and forwarded the claim to the patient's vision plan.

The medical payer treated this as a vision service and sent the claim on for you. Code 297 is used when it does not forward and you must submit to the vision plan yourself.

The next response should come from the vision plan.

Group codes seen with 298

On a remittance, 298 comes after a group code. These are the ones it is most often reported with:

• OA 298 (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.
• CO 298 (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

• A routine eye exam or eyewear was billed to the medical plan.
• The payer handles both medical and vision coverage and routes claims between them.
• The service is excluded under medical and covered under vision.

What to do next

1. Record that the claim was forwarded to the vision plan.
2. Track the vision plan's response and follow up if nothing arrives.
3. Submit directly to the vision plan only if it confirms it never received the claim.

Related codes

• 297 (reason code) Medical plan: bill the vision plan