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N223 Remark Code: No Proof of Benefit in Initial Period

N223 means the payer required documentation that the patient benefited from the treatment during an initial trial or treatment period, and it was not provided. Coverage beyond that period typically depends on showing the treatment helped.

Code: N223 (RARC N223)
Status: Active In use since August 1, 2004.
Code set: Remittance Advice Remark Codes (RARC)
Group codes: CO (Contractual Obligation): Continued services were denied or held for missing documentation. The provider or supplier supplies it; the patient should not be billed while it is correctable.
PR (Patient Responsibility): If the patient cannot show benefit and was properly notified, the plan may assign continued charges to the patient.
Official description: Missing documentation of benefit to the patient during initial treatment period.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What N223 means

Some coverage is provisional. The payer approves an initial period of treatment and continues paying only if the patient benefits. A familiar example is sleep apnea equipment, where many payers require a re-evaluation and objective usage data during the early months before continuing coverage. N223 says the proof that the patient benefited during that initial window was missing.

The remark generally accompanies CARC 252 or CARC 50.

Common causes

The follow-up visit to document benefit never took place, or happened outside the required window.
The clinician saw the patient but did not document the response to treatment.
Objective usage data was available from the device but was not sent.
The supplier billed continued rental without collecting the treating clinician’s note.

How to fix it

Check the payer’s policy for the item or therapy to learn what must be shown and by when.
Collect the re-evaluation note and supporting data, such as usage reports, from the treating clinician and the device.
Send the documentation using the payer’s attachment process, referencing the claim number.
If the re-evaluation was missed, ask the payer what options exist, such as a new trial period, before rebilling.
If the documentation was sent previously, confirm receipt and request reconsideration.

How to prevent it

Schedule the benefit re-evaluation at the time treatment begins, and set reminders for the patient and clinician. Suppliers should track trial period dates and request documentation well before continued billing depends on it.

Codes that may appear with N223

CO-252 (An attachment/other documentation is required to adjudicate this claim/service.): Documentation is required; N223 specifies proof of benefit during the initial period.
CO-50 (These are non-covered services because this is not deemed a 'medical necessity' by the payer.): Without evidence of benefit, continuing treatment may be judged not medically necessary.
CO-272 (Coverage/program guidelines were not met.): Coverage guidelines for continued use were not met.

N224 (Incomplete/invalid documentation of benefit to the patient during initial treatment period.): Documentation of benefit was sent but was incomplete or invalid.
N115 (This decision was based on a Local Coverage Determination (LCD).): The decision was based on a Local Coverage Determination, which may set the benefit requirement.

N223 FAQ

What services have an initial treatment period?

Common examples include positive airway pressure devices, some other durable equipment, and certain therapies where coverage continues only if the patient uses and benefits from the treatment. Rules vary by payer.

What counts as documentation of benefit?

Usually a clinician's note after re-evaluation stating the patient's response, often supported by objective data such as device usage downloads or measured improvement.

Who should provide the documentation?

The treating clinician documents the benefit. For equipment, the supplier typically collects that documentation and sends it to the payer.

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