Skip to main content

N557 Remark Code: File Where Specimen Was Collected

N557 means the claim or service is not payable in this payer's service area. The lab claim must be filed with the payer or plan in whose service area the specimen was collected, not the plan where the lab is located or the one that received it.

Quick facts

Code
N557 (RARC N557)
Status
Active In use since July 1, 2012.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The claim was sent to the wrong plan. Refile with the correct one; do not bill the patient.
Official description
This claim/service is not payable under our service area. The claim must be filed to the Payer/Plan in whose service area the specimen was collected.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N557 means

Some payers are organized regionally, with separate plans covering different service areas. For certain types of claims, those payers set rules about which local plan must receive the claim. For lab services, the rule in N557 ties the claim to the location where the specimen was collected.

So if a specimen was drawn in one plan’s area and sent to a lab in another, the lab typically must file with the plan covering the draw location. N557 says your claim went to the wrong one.

Common causes

  • A reference lab billed its local plan by default for specimens collected in other states.
  • The collection site address was missing, so the claim appeared to originate at the lab.
  • Staff filed with the patient’s home plan based on the ID card instead of following the local-plan rule.
  • The lab’s billing system used a single payer ID for all claims from a regional payer.

How to fix it

  1. Confirm where the specimen was collected from the requisition or order.
  2. Identify the plan that covers that service area under the payer’s rules.
  3. Refile the claim with that plan, reporting the collection location as the payer requires.
  4. Check your filing limits, which continue to run while the claim is misdirected.
  5. Review similar claims from the same collection sites to catch other misrouted submissions.

How to prevent it

Capture the collection site address on every requisition and build routing rules in your billing system based on that address. Labs that receive specimens from many areas benefit most from automated routing.

Codes that may appear with N557

  • CO-109 (Claim/service not covered by this payer/contractor.): The claim is not covered by this payer; send it to the correct payer or contractor.
  • CO-16 (Claim/service lacks information or has submission/billing error(s).): Some payers treat the misdirected claim as a submission error.
  • N558 (This claim/service is not payable under our service area.): The same rule for equipment: file where the equipment was shipped or purchased.
  • N559 (This claim/service is not payable under our service area.): File with the plan in whose service area the ordering physician is located.
  • N104 (This claim/service is not payable under our claims jurisdiction area.): Not payable in this Medicare claims jurisdiction; send to the correct contractor.

N557 FAQ

Which payers use this rule?

It is best known from Blue Cross Blue Shield plans' rules for independent clinical laboratory claims, where the plan in the area the specimen was drawn is responsible. Other payers with regional structures can have similar rules.

How do I know where the specimen was collected?

Use the collection site's address: the physician office, patient service center, or other location where the draw happened. The lab's processing location does not determine it.

Does the patient's home plan matter?

The patient's plan still determines benefits, but under these rules the claim is filed with the local plan in the collection area, which routes it as needed.