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N99 Remark Code: Patient Must Be Able to Keep Voiding Diary

N99 means the payer requires the patient to be able to record voiding diary data well enough for the results of the implant to be evaluated. The claim was denied because the record did not show the patient had that ability.

Code: N99 (RARC N99)
Status: Active In use since August 24, 2001.
Code set: Remittance Advice Remark Codes (RARC)
Group codes: CO (Contractual Obligation): A coverage-criterion denial carried by the provider, unless a valid advance notice makes the patient responsible.
PR (Patient Responsibility): Applies only when the patient accepted financial responsibility in writing before the service.
Official description: Patient must be able to demonstrate adequate ability to record voiding diary data such that clinical results of the implant procedure can be properly evaluated.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What N99 means

Implanted stimulation therapy for urinary symptoms is judged by what the patient records: how often they void, leak, or feel urgency. If the patient cannot produce reliable diary entries, there is no way to show the trial worked or to monitor the device afterward. N99 tells you the payer did not see evidence that the patient could meet that requirement.

It usually explains CARC 50 or a coverage-guideline code. N99 is less about the procedure and more about the patient’s capacity to take part in its evaluation.

Common causes

The chart has no baseline diary, so there is nothing to show the patient can complete one.
Diaries were started but left incomplete or inconsistent.
Notes mention memory, cognitive, or dexterity problems without addressing how diary data is being captured.
Records sent for review omitted the patient education and diary pages.

What to do

Pull the completed diaries and any notes on how the patient was instructed.
Document capability in a brief clinician statement that the patient (or a named caregiver, if the payer accepts it) recorded the data accurately.
Appeal with the diaries attached, and point to where they appear in the record.
If the patient truly cannot keep a diary, the service is unlikely to qualify. Determine liability based on whether an advance notice was obtained.

How to prevent it

Treat the baseline diary as a gate in the work-up. If the patient struggles to complete it, address that before proceeding to a trial or implant, and record the outcome. Keeping diary pages in a consistent section of the chart makes record requests quicker to fill.

Codes that may appear with N99

CO-50 (These are non-covered services because this is not deemed a 'medical necessity' by the payer.): Not medically necessary because a required patient criterion was not documented.
CO-272 (Coverage/program guidelines were not met.): The device's coverage guidelines were not met.

N98 (Patient must have had a successful test stimulation in order to support subsequent implantation.): Requires a successful trial measured through the same diaries.
N96 (Patient must be refractory to conventional therapy (documented behavioral, pharmacologic and/or surgical corrective therapy) and be an appropriate…): Covers the refractory and surgical candidate criteria.
N97 (Patients with stress incontinence, urinary obstruction, and specific neurologic diseases (e.g., diabetes with peripheral nerve involvement) which…): Names the conditions excluded from coverage.

N99 FAQ

What if a caregiver keeps the diary?

Payer interpretations vary. If a caregiver records the data reliably, document who keeps the diary and how, and check the payer's policy on whether that satisfies the requirement.

How do I show the patient can keep a diary?

The best evidence is completed baseline diaries in the record, with a note that the patient understood and followed the instructions.

Is N99 about cognitive impairment?

It can be, but also physical limitations or any factor that prevents accurate recording. The criterion is the ability to produce usable data, not a specific diagnosis.

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