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N299 Remark Code: Occurrence Date Missing or Invalid

N299 means one or more occurrence dates on the claim were missing, incomplete, or invalid. On institutional claims, each occurrence code must be paired with the date the event happened, and the payer could not accept a date reported.

Quick facts

Code
N299 (RARC N299)
Status
Active In use since December 2, 2004.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The facility must correct the occurrence date and resubmit. The patient is not liable for the adjustment.
Official description
Missing/incomplete/invalid occurrence date(s).
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N299 means

Institutional claims use occurrence codes to tell the payer about events that affect how the claim is processed: an accident that may point to another payer, the date symptoms began, or when a therapy plan was established. Every occurrence code has a partner date, and the two travel together in UB-04 form locators 31 to 34.

N299 says one of those dates was blank, formatted incorrectly, or implausible for the code it accompanies. Because occurrence codes can change coverage and coordination of benefits decisions, payers won’t guess; they return the claim with N299 and usually CARC 16.

Common causes

  • An occurrence code was entered but the date field was left empty.
  • The date was keyed in the wrong format or with an impossible value (for example, a 13th month).
  • The date conflicts with the claim: an accident date later than the admission, or an onset date in the future.
  • Codes and dates got out of alignment when several occurrences were entered, so each date sits beside the wrong code.
  • A code carried over from a prior claim template kept its old date.

How to fix it

  1. List every occurrence code on the claim and identify which one the payer flagged, if the remit specifies.
  2. Confirm each event’s actual date in the medical record or registration notes.
  3. Correct the date, and make sure each code and date are in the same form locator pair.
  4. Delete any occurrence codes that don’t belong on this claim.
  5. Submit a replacement claim with frequency code 7 and the original claim number.

How to prevent it

Build edits that reject any occurrence code without a date and any date that falls outside logical bounds for the code. Registration should capture accident and onset dates in structured fields rather than notes, so they flow into occurrence entries correctly. See our CARC 16 guide for more on data-element denials.

Codes that may appear with N299

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): Missing or invalid information; N299 identifies an occurrence date.
  • M45 (Missing/incomplete/invalid occurrence code(s).): The occurrence code itself, not its date, is missing or invalid.
  • N300 (Missing/incomplete/invalid occurrence span date(s).): An occurrence span date (a from/through range) is the problem.
  • N832 (Duplicate occurrence code/occurrence span code.): The claim reported a duplicate occurrence code or occurrence span code.
  • N305 (Missing/incomplete/invalid injury/accident date.): The injury or accident date specifically is the problem.

N299 FAQ

Where do occurrence codes and dates go?

UB-04 form locators 31 through 34, each holding a code and its date. The 837I reports them together as occurrence information.

What is an occurrence code?

A two-character code describing a significant event related to the claim, such as an accident, the onset of symptoms, or the start of a therapy plan. Each code needs a date.

Can the occurrence date be after the service dates?

Some occurrence events can fall outside the billing period, but a date that doesn't make sense for the code, such as an accident after the admission, will usually fail.