N421Remark Code (RARC)Active
Effective 08/01/2007 · Updated 05/08/2008

N421 Remark Code - Retroactive Adjustment Explanation

The N421 remark code indicates that the claim payment was affected by a retroactive adjustment from the payer based on a review organization’s decision. This means that the payment amount you received has been altered due to a review process that took place after the initial claim was processed.

How It Relates to the Denial

The N421 remark code typically accompanies a Claim Adjustment Reason Code that details the specific adjustment being made. Together, they signal that a payment change has occurred as a result of a review organization's evaluation.

Common Scenarios

1A provider submitted a claim for a surgical procedure, and the payment was initially approved. Later, the remittance shows a reduced payment along with the N421 code.
→ In this case, the N421 remark indicates that the reduced payment is due to a retroactive adjustment stemming from a review organization’s decision regarding the claim.
2An outpatient therapy claim was originally paid but later adjusted down, and the remittance includes both a Claim Adjustment Reason Code and the N421 remark code.
→ The presence of the N421 remark suggests that the adjustment was influenced by a review process, meaning the payer has reassessed the claim post-payment.
3A claim for diagnostic testing was paid but was later adjusted due to a payer's review, accompanied by the N421 remark on the remittance advice.
→ This signifies that the payment change is a result of a decision made by a review organization, which may have determined that the services rendered did not meet the criteria for the original payment.

What to Do

  1. Review the accompanying Claim Adjustment Reason Code for details on the specific adjustment.
  2. Consider contacting the payer for clarification on the review organization's decision if the adjustment seems unjustified.

What to Check

  • The original claim submission details to understand the services billed.
  • The payment history for any prior adjustments related to this claim.
  • Documentation from the review organization if available, to see the basis for their decision.