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N464 Remark Code: Incomplete or Invalid Support Data

N464 means the support data for the claim was incomplete or invalid. The payer received supporting information or documentation, but it did not meet requirements, did not match the claim, or was missing pieces, so the claim could not be paid as billed.

Quick facts

Code
N464 (RARC N464)
Status
Active In use since July 1, 2008.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The payer needs complete, valid support before paying. The provider fixes and resubmits; the patient is not billed.
Official description
Incomplete/invalid support data for claim.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N464 means

N464 is the “received but not good enough” counterpart to N463. The payer has supporting data, but it is incomplete, inconsistent with the claim, or not in a form the payer accepts. Like N463, it is broad, so the specific problem usually has to be identified from a letter, another remark, or a call.

Payers often pair N464 with CARC 251, sometimes with CARC 16 when the issue is in the claim data itself.

Two ways support data fails

The documents are deficient. Missing pages, unsigned records, the wrong date of service, a different patient, or content that does not address what the payer’s policy requires.

The data doesn’t match. The support describes something different from the claim: other units, a different procedure, a different provider, or dates outside the billing period.

Deciding which applies tells you whether to fix the documents, the claim, or both.

What to do

  1. Identify the deficiency from the payer’s notice or by phone. Write down the exact element that failed.
  2. Compare the support with the claim, field by field, for mismatches.
  3. Fix the source. Get complete, signed documents, or correct the claim and send it with resubmission code 7.
  4. Resubmit through the correct channel with a cover note stating what was corrected.
  5. Escalate to an appeal if you believe the support was adequate.

How to prevent it

Before sending supporting data, have someone other than the preparer check it against the claim and the payer’s policy. That second look catches most mismatches. Claims Validator can help catch claim-side inconsistencies before the claim goes out.

Codes that may appear with N464

  • CO-251 (The attachment/other documentation that was received was incomplete or deficient.): The attachment or documentation received was incomplete or deficient.
  • CO-250 (The attachment/other documentation that was received was the incorrect attachment/document.): The wrong attachment was received, and the expected one is still missing.
  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim contains a billing error or missing information.
  • N463 (Missing support data for claim.): Support data for the claim was not received at all.
  • N379 (Claim level information does not match line level information.): Claim-level information does not match line-level information.

N464 FAQ

How do I know which part of my support data failed?

Look for a letter or additional remarks explaining it. If there is none, call the payer and ask which element or document was deficient.

Is N464 about attachments or claim data?

It can be either. Some payers use it when documentation is deficient, others when supporting data elements on the claim itself are invalid.

Do I resubmit the claim or just the documents?

Follow the payer's instructions. If the claim data was wrong, submit a corrected claim. If only the documentation was deficient, a reconsideration with new documents may be enough.