OA-252: Attachment Required to Adjudicate Claim

What Does OA-252 Mean?

When paired with Group Code OA, the documentation request typically involves a secondary payer needing additional information for coordination of benefits adjudication. The most common scenario is the secondary payer requiring the primary payer's Explanation of Benefits to determine its payment liability.

CARC 252 signals that the payer received your claim but cannot complete adjudication because supporting documentation is missing. This is not a coverage determination or a judgment on medical necessity — the payer simply needs more information before it can make a payment decision.

The specific documentation needed varies by payer and service type. Common examples include clinical notes, operative reports, test results, prior authorization letters, or Explanation of Benefits from a primary payer. The accompanying RARC codes on the remittance advice are critical because they pinpoint exactly which documents the payer is requesting.

This code appears frequently on claims for services that commonly require attachments, such as complex procedures, services requiring prior authorization documentation, or secondary claims needing the primary payer's EOB. Tracking patterns of CARC 252 denials by payer can reveal systematic documentation gaps in your billing workflow.

Common Causes

How to Resolve

1. Review RARC codes for secondary payer requirements Check the accompanying RARC codes to identify what the secondary payer needs. N479 (missing EOB) is the most common pairing in OA-252 scenarios.
2. Obtain the primary payer's EOB If not already available, obtain the primary payer's Explanation of Benefits showing how the primary claim was adjudicated, including allowed amounts and patient responsibility.
3. Gather any additional supporting documentation Collect any other documents the secondary payer requires beyond the EOB, such as clinical notes or medical records specified by additional RARC codes.
4. Submit documentation to the secondary payer Send the primary payer's EOB and any additional required documents to the secondary payer with the corrected claim submission.
5. Follow up on secondary claim processing Monitor the resubmitted secondary claim and follow up to ensure it is processed with the submitted documentation.
6. Appeal if documentation was previously submitted If the required documentation was already submitted and the secondary payer failed to process it, file a formal appeal with proof of prior submission and include the documentation again.

Common RARC Pairings

The RARC code tells you exactly what triggered the OA-252:

How to Prevent OA-252

• Always attach the primary payer's EOB when filing secondary claims as this is typically required for COB processing
• Check the secondary payer's attachment requirements before submission and include all required documentation upfront
• Use electronic attachment submission (X12 275 transaction or equivalent) to ensure the secondary payer receives all required documents

Also Filed As

The same CARC 252 may appear with different Group Codes:

Related Denial Codes