Skip to main content

CO-63 Denial Code (Deactivated): Correction to Prior Claim

CO-63 labeled an adjustment as a correction to a prior claim. X12 deactivated it without naming a replacement. Current remittances generally show corrections as a reversal of the original claim followed by the corrected claim.

X12 deactivated CARC63 on October 16, 2003. Payers should no longer use it on new remittances, but it can still appear on older ERAs, corrected claims, and appeals.

Quick facts

Code
CO-63 (CARC 63)
Status
Deactivated StoppedOctober 16, 2003 (in use since January 1, 1995).
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The adjustment reflected the payer's correction and was not a patient liability.
Official description
Correction to a prior claim.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-63 meant

CARC 63 was a bookkeeping signal rather than a denial. It told the provider that the amounts shown were the payer correcting how it had processed an earlier claim, perhaps because of a pricing error, a data entry mistake, or a corrected claim the provider submitted.

What replaced it

X12 did not name a successor. The 835 format handles corrections structurally: the payer reverses the original claim and then sends the corrected version, so a separate “this is a correction” adjustment code became unnecessary.

When a payer does need to explain a correction with a code, nearby active choices include CO-129 for prior processing information that appears incorrect, CO-B13 for claims already paid earlier, and CO-193 when a review confirms the original decision.

If you still see CO-63

It belongs to older remittance formats, so expect it in archived payment files or legacy system reports. When reconciling, find the original payment for the same claim and compare it to the corrected figures, so you post only the difference.

If the correction produced a negative balance or a recoupment you did not expect, contact the payer for an explanation before accepting it.

  • CO-129 (Prior processing information appears incorrect.): Prior processing information appears incorrect, with a remark code explaining what.
  • CO-B13 (Previously paid.): Previously paid; payment may have been made in an earlier remittance.
  • CO-193 (Original payment decision is being maintained.): The original payment decision is being maintained after review.

CO-63 FAQ

How do corrected claims show on remittances now?

Payers generally reverse the original claim, showing the prior payment backed out, and then report the corrected claim with its new payment and adjustments. Reviewing both entries together shows the net change.

Do I need to do anything when I see CO-63?

Usually not beyond posting. Compare the corrected amounts to the original payment so your ledger reflects the net result, and check that no overpayment or underpayment remains.