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N338 Remark Code: Shipped Date Missing or Invalid

N338 means the date an item was shipped to the patient was missing, incomplete, or invalid. Payers use it to confirm when mailed supplies or equipment left the supplier, and some use it as the date of service.

Quick facts

Code
N338 (RARC N338)
Status
Active In use since December 2, 2004.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The claim was denied because the shipping date could not be validated. The supplier corrects it; the patient is not billed for this adjustment.
Official description
Missing/incomplete/invalid shipped date.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N338 means

Suppliers who mail diabetic supplies, CPAP supplies, ostomy products, or other items to patients often have to report when the order shipped. The ship date lets the payer check the order sequence (order before shipment, shipment before billing) and, for some payers, it stands in as the date of service. N338 says that date was absent or didn’t fit.

It usually explains CARC 16. When a ship date is later than the billing date, CARC 110 may appear as well.

Common causes

  • The billing system used the order-entry date and never recorded the actual carrier pickup date.
  • The ship date field was blank because staff entered only the delivery date.
  • A partial shipment went out in stages, and the claim date matched none of them.
  • The claim was billed before the item shipped, creating a future date.
  • A drop-shipped item from a manufacturer never had its ship date passed back to the supplier.

How to fix it

  1. Get the carrier record. Use tracking data or the shipping manifest to confirm the exact ship date for each item on the claim.
  2. Apply the payer’s date rule. Decide whether the payer wants the ship date or delivery date as the date of service, then line up the service dates.
  3. Correct the claim. Report the ship date where the payer requires it and adjust any line dates that were wrong.
  4. Resubmit with frequency code 7 and the original claim number.
  5. Split shipments onto separate lines or claims if the payer requires one date per shipment.

How to prevent it

Integrate your shipping system with billing so the tracking record writes the ship date straight to the claim. Hold claims until tracking confirms shipment, and review drop-ship vendors’ reports to be sure dates come back before billing.

Codes that may appear with N338

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): Claim information is incomplete; N338 identifies the shipped date.
  • CO-110 (Billing date predates service date.): The billing date predates the service date, which can happen when a ship date is reported incorrectly.
  • N304 (Missing/incomplete/invalid dispensed date.): Used when the dispensed date is missing or invalid.
  • N397 (Benefits are not available for incomplete service(s)/undelivered item(s).): Indicates benefits are not available for items that were not delivered.
  • N331 (Missing/incomplete/invalid physician order date.): Covers a missing or invalid physician order date, which must precede shipment.

N338 FAQ

Is the shipped date the same as the date of service?

It can be. Some payers, including Medicare for many mail-order DME supplies, allow the shipping date to be used as the date of service. Others use the delivery date. Follow the payer's rule consistently.

What proof of shipment should I keep?

Keep the carrier's tracking record or shipping invoice showing the date, the patient's address, and the items shipped. Payers may request it on audit.

What if the item was shipped but returned?

Do not bill for an item the patient never received. Hold or void the claim until the item is actually delivered.