Skip to main content

N812 Remark Code: Service Date Span Over 18 Months

N812 means the service dates on the claim span more than 18 months from start to end. The payer won't accept a claim covering that long a period, so the services must be split into claims with shorter date ranges.

Quick facts

Code
N812 (RARC N812)
Status
Active In use since November 1, 2018.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The claim was rejected or denied for a date-range error the provider corrects. It is not a patient balance.
Official description
The start service date through end service date cannot span greater than 18 months.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N812 means

Every claim, and every line on it, has a start and end date of service. N812 applies an outer limit: the distance between the earliest start date and the latest end date can’t exceed 18 months. When it does, the payer returns N812, generally with CARC 16, and doesn’t adjudicate the services.

In real billing, a genuine 18-month span on one claim is rare. N812 is more often a sign of a typo than of intentional batching.

Common causes

  • Wrong year. A from date keyed as last year, or a through date keyed a year ahead.
  • Old charges merged with new ones. A forgotten charge from long ago was swept onto a current claim for the same patient.
  • Long-running services billed together, such as months of equipment rental or recurring treatment placed on one claim.
  • Default dates in templates that weren’t updated.

How to fix it

  1. Check every line’s dates in box 24A and the claim-level dates against the chart.
  2. Correct typos. If a year was simply wrong, fix it and resubmit.
  3. Split genuine long spans into separate claims that follow the payer’s rules for the service type, such as one claim per month or per calendar year.
  4. Review timely filing for the oldest services before rebilling. See timely filing denials.
  5. Submit correctly. Use new claims after a front-end rejection or a corrected claim with resubmission code 7 in box 22 after an adjudicated denial.

How to prevent it

  • Add a claim edit that flags any date span longer than a few months for review.
  • Don’t let the system attach aged, unbilled charges to new claims automatically.
  • See claim rejection vs. denial to know whether a split claim goes out as new or corrected.

Codes that may appear with N812

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): A submission or billing error; N812 says it's the length of the date span.
  • CO-267 (Claim/service spans multiple months.): The claim spans multiple months, a related split requirement.
  • N800 (Only one service date is allowed per claim.): Only one service date allowed per claim, a stricter version of the same idea.
  • CO-268 (The Claim spans two calendar years.): The claim crosses two calendar years and must be split by year.
  • N797 (Missing/incomplete/invalid date qualifier.): A date on the claim lacks a valid qualifier.

N812 FAQ

How could a claim span 18 months?

Usually through a data entry error, such as a wrong year in the from or through date, or through batching long-running services like rentals, therapy, or long-term care onto one claim.

Is the date span also a timely filing risk?

Yes. If the earliest dates are that old, some services may already be past the payer's filing limit. Check timely filing before rebilling.

Should I split by month or by year?

Follow the payer's rules for the claim type. Many require monthly or calendar-year claims for recurring services; others accept any span within their limits.