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N835 Remark Code: Unrelated Service Reduced to Patient

N835 means the payer reduced the service because it was unrelated to the condition or claim it is responsible for, and the remaining balance of the charge is the patient's responsibility. It is commonly seen where coverage is tied to a specific injury, such as workers' compensation or auto claims.

Code: N835 (RARC N835)
Status: Active In use since November 1, 2020.
Code set: Remittance Advice Remark Codes (RARC)
Group codes: PR (Patient Responsibility): The balance of the charge is patient responsibility, as the remark states. Check any contract or state rules before billing.
CO (Contractual Obligation): If a CO adjustment also appears, that part is a provider write-off and can't be moved to the patient.
Official description: Unrelated Service/procedure/treatment is reduced. The balance of this charge is the patient's responsibility.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What N835 means

Some payers only cover care related to a specific condition. Workers’ compensation carriers pay for treatment of the accepted work injury, and auto insurers for injuries from the covered accident. When a visit includes care for something else, the payer can pay only the related portion.

N835 is how the payer reports that: it reduced the unrelated service and assigned the rest of the charge to the patient. Unlike many remark codes, its text states plainly that the balance is patient responsibility, so it usually appears under PR.

Common causes

Visits addressing more than one condition, such as the work injury plus an unrelated chronic problem.
Diagnosis codes on the claim that point to conditions other than the accepted one.
Services the adjuster considers unrelated to the accepted body part or injury.
Changes in the accepted condition after the carrier reviews the claim.

What to do

Review the diagnoses and documentation to confirm which services treated the accepted condition.
If the payer misjudged relatedness, send a reconsideration with records linking the service to the accepted injury.
Bill the patient’s health plan for the unrelated portion where appropriate, including the remittance.
Bill the patient only for what remains, and only as state rules allow.

How to prevent it

Separate injury-related and unrelated services on different claims when they’re provided at the same visit.
Point each line to the right diagnosis in box 24E.
Confirm the accepted condition and body part with the adjuster before treatment.

Codes that may appear with N835

CO-P2 (Not a work related injury/illness and thus not the liability of the workers' compensation carrier): Not a work-related injury or illness, so not the liability of the workers' compensation carrier.
CO-P13 (Payment reduced or denied based on workers' compensation jurisdictional regulations or payment policies, use only if no other code is applicable.): Payment reduced or denied under workers' compensation jurisdictional rules.

N607 (Service provided for non-compensable condition(s).): The service was provided for a non-compensable condition.
N839 (The procedure code was added/changed because the level of service exceeds the compensable condition(s).): The procedure code was changed because the level of service exceeded the compensable condition.
CO-P4 (Workers' Compensation claim adjudicated as non-compensable.): The whole workers' compensation claim was found non-compensable.

N835 FAQ

Can I bill the patient's health insurance for the unrelated portion?

Often yes. If the patient has health coverage, submit the unrelated portion to that plan with the N835 remittance, following its coordination rules.

How does the payer decide what's unrelated?

It compares the service and diagnoses with the accepted injury or condition on file. Services for other conditions, or partly for other conditions, may be reduced.

Are there limits on billing the patient?

Workers' compensation and auto rules vary by state, and some restrict billing injured workers during a claim. Confirm the state rules before sending a statement.

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