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N898 Remark Code: Missing or Invalid RUG Code

N898 means the Resource Utilization Group (RUG) code or codes needed to price the claim were missing, incomplete, or invalid. RUGs classify nursing facility residents by care needs, and some payers, mainly state Medicaid programs and certain contracts, still use them to set daily rates.

Quick facts

Code
N898 (RARC N898)
Status
Active In use since July 1, 2024.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The unpaid amount while the RUG code is missing or invalid. It is the facility's responsibility to correct.
Official description
Missing/incomplete/invalid Resource Utilization Group(s) (RUG) code(s).
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N898 means

Resource Utilization Groups sort nursing facility residents into categories that reflect the care and resources they need. Each group carries a payment weight, so the RUG code on a claim drives how much the payer pays per day.

N898 means the payer could not use the RUG information on your claim. It was absent, only partly reported, or did not validate against the payer’s rules.

Common causes

  • The payer switched classification versions and the claim still uses the old one.
  • The RUG code was left off when billing a payer that still requires it, often after Medicare moved to PDPM.
  • The code on the claim does not match the resident’s current assessment.
  • Billing periods and assessment periods do not line up.

How to fix it

  1. Confirm which classification system the payer requires, for example which RUG version.
  2. Check the resident’s assessment and the RUG code it generates for the billing period.
  3. Correct the claim and resubmit with frequency code 7, or follow the payer’s rebilling instructions.
  4. Fix the assessment first if the RUG code is wrong because the assessment data is wrong.

How to prevent it

Keep a payer matrix showing which programs need RUG codes, which version, and which need PDPM HIPPS codes, and have claim edits check for them before billing.

Codes that may appear with N898

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim lacks information or has a billing error; N898 points to the RUG code.
  • CO-A1 (Claim/Service denied.): A general denial with N898 explaining the specific issue.
  • MA66 (Missing/incomplete/invalid principal procedure code.): A different institutional data element, the principal procedure code, is missing or invalid.
  • CO-190 (Payment is included in the allowance for a Skilled Nursing Facility (SNF) qualified stay.): Payment is included in the allowance for a skilled nursing facility qualified stay.
  • CO-186 (Level of care change adjustment.): A level-of-care change adjustment, which can accompany classification changes.

N898 FAQ

Doesn't Medicare use PDPM now?

Yes. Medicare's skilled nursing facility payment system replaced RUG-IV with the Patient Driven Payment Model in October 2019. RUG codes remain in use for some Medicaid nursing facility programs and some commercial or managed care contracts.

Where does the RUG code come from?

It is derived from the resident's assessment data, typically the Minimum Data Set, using the classification version the payer requires.

What makes a RUG code invalid?

Common reasons are using a version the payer does not accept, a code that does not match the assessment on file, or dates that fall outside the assessment's coverage period.