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N738 Remark Code: Incomplete Vein Study Report

N738 means the payer received a vein study report, usually a venous duplex ultrasound, but found it incomplete or invalid. Payers often rely on this report to decide coverage for vein treatment procedures, so the claim waits for a usable one.

Quick facts

Code
N738 (RARC N738)
Status
Active In use since March 1, 2015.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The provider carries the adjustment while the vein study documentation is deficient.
Official description
Incomplete/invalid Vein Study Report.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N738 means

Coverage for varicose vein and venous insufficiency treatment is often conditioned on imaging findings. The vein study report, typically a duplex ultrasound interpretation, documents which veins are affected and how. N738 says the payer received this report but could not use it to confirm coverage.

The remark is usually paired with CARC 251, CARC 50, or CARC 272. Payers that apply detailed vein treatment policies may reject a report that lacks even one measurement their criteria depend on.

Common causes

  • The report omits which vein segments were evaluated or on which side.
  • Reflux findings are described without the measurements the payer’s policy uses.
  • The interpreting physician did not sign the final report.
  • The study date falls outside the payer’s accepted window before treatment.
  • The report addresses one leg while the procedure was on the other.

How to fix it

  1. Read the payer’s vein treatment policy and identify the exact element the report is missing.
  2. Obtain the final signed report, and the worksheet if it contains the measurements.
  3. If the report is accurate but lacks detail, ask the interpreting physician whether a dated addendum is appropriate.
  4. Check that laterality and treated segments on the claim match the study. Correct the claim with resubmission code 7 if needed.
  5. Resubmit the report through reconsideration or appeal, referencing the claim.

How to prevent it

Build payer-required fields into the vein study template, and review the study against the policy before scheduling treatment, when prior authorization is often requested anyway.

Codes that may appear with N738

  • CO-251 (The attachment/other documentation that was received was incomplete or deficient.): The documentation received was incomplete or deficient.
  • CO-50 (These are non-covered services because this is not deemed a 'medical necessity' by the payer.): The payer could not confirm medical necessity from the report it received.
  • CO-272 (Coverage/program guidelines were not met.): Coverage guidelines for the vein procedure were not shown to be met.
  • N739 (Missing Vein Study Report.): No vein study report was received.
  • N240 (Incomplete/invalid radiology report.): An incomplete radiology report, used by some payers for imaging studies generally.
  • N458 (Incomplete/invalid Diagnostic Report.): An incomplete diagnostic report of any kind.

N738 FAQ

What does a vein study report need to show?

Payer policies differ, but they often look for which veins were studied, whether reflux was present and how it was measured, vein size, and the interpreting physician's conclusion, all signed and dated.

Does the vein study need to be recent?

Many payers set a window between the study and the procedure. Check the payer's vein treatment policy for the timeframe that applies.

Can I send a technologist worksheet instead of the report?

A worksheet may supplement the report, but most payers want the physician's interpreted and signed report.