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N173 Remark Code: Qualifying Hospital Stay Dates Missing

N173 means the payer could not find the dates of the qualifying hospital stay that the episode of care depends on. It is most often seen on skilled nursing facility claims, where coverage hinges on a prior inpatient stay.

Quick facts

Code
N173 (RARC N173)
Status
Active In use since February 28, 2003.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The claim was denied or held because the qualifying stay information was absent. The provider can usually correct the claim, and the amount should not be billed to the patient while that is possible.
  • PR (Patient Responsibility): Less common. If the payer determines no qualifying stay actually occurred, the patient may be responsible, depending on the plan and any notices given before care.
Official description
No qualifying hospital stay dates were provided for this episode of care.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N173 means

Certain benefits only apply after the patient has been an inpatient in a hospital for a qualifying period. Skilled nursing facility coverage under Medicare and many Medicare Advantage and commercial plans works this way. When the payer receives a claim for that kind of care and cannot find the admission and discharge dates of the qualifying hospital stay, it returns N173.

The remark code typically accompanies CARC 16 (information missing) when the dates were simply omitted. If the payer goes further and decides the stay did not meet its rules, you are more likely to see an eligibility or coverage reason code instead.

Common causes

  • The qualifying stay dates were never keyed onto the UB-04 or 837I. On institutional claims these are usually reported as an occurrence span (commonly occurrence span code 70 for SNF qualifying stays), but confirm the exact convention with the payer.
  • The span was entered with the wrong code, so the dates are present but not recognised as a qualifying stay.
  • The from and through dates are reversed, incomplete, or fall outside a sensible window relative to the SNF admission.
  • An interim or continuing claim dropped the span that appeared on the first bill in the series.
  • The patient came from a hospital stay that was billed as observation, so there is no inpatient admission to report.

How to fix it

  1. Pull the hospital discharge information from the referral packet or the transferring hospital to confirm the inpatient admission and discharge dates.
  2. Verify the stay was an inpatient admission and not outpatient observation time.
  3. Add the qualifying stay dates in the payer’s required field and check that the code used for the span is correct.
  4. Submit a replacement claim (frequency code 7 on institutional claims) referencing the original claim number, unless the payer tells you to send a new claim.
  5. If the payer indicates the stay itself did not qualify, review whether a waiver or plan-specific exception applies before appealing.

How to prevent it

Capture hospital admission and discharge dates at SNF intake and store them where your billing system can populate the claim automatically. Build an edit that stops any post-acute claim from releasing without a qualifying span. It also helps to confirm inpatient versus observation status with the discharging hospital before admission, since that question determines whether a qualifying stay exists at all.

Codes that may appear with N173

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim is missing information needed to adjudicate it; N173 names the qualifying stay dates as the gap.
  • CO-177 (Patient has not met the required eligibility requirements.): Used when the payer concludes the patient did not meet eligibility requirements, such as a required prior hospital stay.
  • CO-272 (Coverage/program guidelines were not met.): Coverage or program guidelines were not met, which can include the prior-stay condition for post-acute benefits.
  • N300 (Missing/incomplete/invalid occurrence span date(s).): Points to missing or invalid occurrence span dates, the general field family where stay dates are reported.
  • N47 (Claim conflicts with another inpatient stay.): Flags a claim that conflicts with another inpatient stay rather than one that omits the stay.
  • CO-190 (Payment is included in the allowance for a Skilled Nursing Facility (SNF) qualified stay.): Explains that a service was included in the allowance for a qualified SNF stay.

N173 FAQ

Which claims usually receive N173?

Mostly institutional post-acute claims, especially skilled nursing facility bills, where benefits depend on a preceding inpatient hospital stay. Some payers use it for other episode-based benefits too.

Does N173 mean the patient never had a qualifying stay?

Not necessarily. It says the dates were not provided. If the stay happened, adding the dates and resubmitting is normally enough; if it did not, the claim may be denied on coverage grounds instead.

Do I need to send hospital records?

Usually the dates on the claim are what is missing. Some payers may ask for the discharge summary or hospital records as well, so check the remittance and payer instructions.