Look up another code

N176 Remark Code: Shipboard Services Coverage Rules

N176 means the service was provided aboard a ship and did not meet the coverage conditions: the ship must be of United States registry, in United States waters, and the service must come from a doctor licensed to practice in the United States.

Code: N176 (RARC N176)
Status: Active In use since February 28, 2003.
Code set: Remittance Advice Remark Codes (RARC)
Group codes: PR (Patient Responsibility): If the service was simply outside the plan's shipboard coverage rules, the patient may be responsible, subject to the plan's terms.
CO (Contractual Obligation): Where the provider billed incorrectly or the payer's rules shift the loss to the provider, the amount is a provider adjustment.
Official description: Services provided aboard a ship are covered only when the ship is of United States registry and is in United States waters. In addition, a doctor licensed to practice in the United States must provide the service.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What N176 means

N176 is a coverage explanation, not a data error. The payer has concluded that the service took place on a ship and that the ship-based care did not satisfy all three conditions in the remark: the vessel must be registered in the United States, it must be within United States waters when the service happens, and the treating doctor must hold a US license.

Medicare’s rules for services furnished outside the United States are the classic source of this language, and the remark commonly appears alongside CARC 96 (non-covered charges) or CARC 58 (inappropriate place of service).

Common causes

The patient was treated by a ship’s medical staff on a foreign-flagged cruise vessel.
The ship had left US territorial waters by the time care was given.
The treating physician was licensed outside the United States.
The claim reported a ship-related place or location in error when care was actually provided ashore.

What to do

Confirm the facts: where the ship was, its flag of registry, and the treating doctor’s licensure. Ship logs or the medical department’s records often show time and location.
If any detail on the claim was wrong, correct it and submit a replacement claim with resubmission code 7 and the original claim number.
If all the facts support coverage, appeal with evidence of registry, location, and licensure.
If the service is genuinely outside the rule, explain to the patient that the plan does not cover it and review whether a travel or supplemental policy might apply.

How to prevent it

Providers who treat patients at sea should document vessel registry and position with every encounter and verify their own licensure status for US payers. Patients planning cruises may want to ask their plan about coverage limits before travelling.

Codes that may appear with N176

CO-96 (Non-covered charge(s).): Non-covered charges; N176 explains the non-coverage is due to the shipboard location.
CO-58 (Treatment was deemed by the payer to have been rendered in an inappropriate or invalid place of service.): The payer considered the place of service inappropriate or invalid for the treatment.
PR-204 (This service/equipment/drug is not covered under the patient's current benefit plan): The service is not covered under the patient's current benefit plan in this setting.

N79 (Service billed is not compatible with patient location information.): Service billed is not compatible with patient location information.
CO-170 (Payment is denied when performed/billed by this type of provider.): Denied because of the type of provider who performed or billed the service.

N176 FAQ

Who typically sees N176?

Ship's physicians, cruise medical providers, and patients who submit claims for care received at sea. Medicare is the best-known payer with this rule, but other plans may apply similar language.

Can a corrected claim fix N176?

Only if the claim information was wrong, for example if the service was actually delivered in a port facility on land or the registry or location details were misreported.

What if the ship was in US waters but foreign registered?

The official wording requires both US registry and US waters, plus a US-licensed doctor. Failing any one condition is enough for this remark to apply.

Important: read before using this information

This page is general educational information about a standard industry code set. It is not medical billing, coding, legal, reimbursement, or compliance advice, and it does not create a professional or advisory relationship with ClaimsRevenue.

Code definitions, payer usage, contracts, and laws change, and payers may apply the same code differently. The information is provided “as is,” without warranties of any kind, express or implied, including accuracy, completeness, or currency. You are solely responsible for verifying it against the current official X12 code lists, CMS guidance, your payer contracts, and payer policies before relying on it, and for every billing, coding, collection, and appeal decision you make.

Using this information does not guarantee that any claim will be paid or that any appeal will succeed. To the fullest extent permitted by law, ClaimsRevenue and MOODRX LLC are not liable for any loss or damage arising from its use. Official code descriptions are published by X12 and are quoted for reference only. See our full Claims Validation Disclaimer.