OA 136 denial code

Claim adjustment reason code 136. Often reported as OA 136.

Prior payer's coverage rules not followed

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 136 means

The claim was cut back because the coverage rules of the payer that processed it first were not followed.

When a patient has more than one plan, the secondary payer may limit what it pays if the primary plan's requirements (such as authorization, network or documentation rules) were not met. This code is used only with group code OA.

In practice the secondary payer is saying it will not make up for money lost because the primary claim was handled outside that plan's rules.

Group codes seen with 136

On a remittance, 136 comes after a group code. These are the ones it is most often reported with:

• OA 136 (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 or reduced the claim because an authorization was missing.
• The service was out of network for the primary plan, so the primary paid less than it could have.
• Documentation or filing rules required by the primary payer were not met.

What to do next

1. Review the primary remittance to see why the primary payer reduced or denied the claim.
2. Fix the issue with the primary payer first, for example by appealing with the authorization or records.
3. Rebill the secondary payer with the corrected primary remittance once the primary claim is resolved.

Related codes

• 22 (reason code) Another payer may be primary
• 23 (reason code) Prior payer payment affected this claim