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CO-71 Denial Code (Deactivated): Primary Payer Amount

CO-71 identified the amount paid by the primary payer when a secondary payer processed the claim. X12 deactivated it and its notes point payers to CARC 23, which covers the impact of prior payer adjudication.

X12 deactivated CARC71 on June 30, 2000. Payers should no longer use it on new remittances, but it can still appear on older ERAs, corrected claims, and appeals.

Code: CO-71 (CARC 71)
Status: Deactivated StoppedJune 30, 2000 (in use since January 1, 1995).
Code set: Claim Adjustment Reason Codes (CARC)
Group codes: OA (Other Adjustment): The prior payer's amount is usually reported as an other adjustment, since it is neither contractual nor patient responsibility.
Official description: Primary Payer amount.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What CO-71 meant

When a patient has more than one plan, the secondary payer looks at what the primary already paid before deciding its own payment. CARC 71 was the early way of showing that primary payment on the secondary’s remittance, so the provider could see why the secondary paid less than its full allowance.

What replaced it

X12’s note is simply “Use code 23.” OA-23 now reports the impact of prior payer adjudication, covering both what the primary paid and what it adjusted. It is restricted to the OA group code.

Two related active codes are OA-22, used when another payer may be primary under coordination of benefits, and OA-136, used when the prior payer’s coverage rules were not followed.

If you still see CO-71

It was retired decades ago, so it should only appear in very old secondary remittances. For posting, treat it as an offset for the primary’s payment and do not write it off. When working any secondary claim today, attach or transmit the primary’s payment details, then compare the secondary’s CARC 23 amount against the primary remittance to confirm they agree.

OA-23 (The impact of prior payer(s) adjudication including payments and/or adjustments. (Use only with Group Code OA)): Named replacement: the impact of prior payers' adjudication, including payments and adjustments.
OA-22 (This care may be covered by another payer per coordination of benefits.): The care may be covered by another payer per coordination of benefits.
OA-136 (Failure to follow prior payer's coverage rules. (Use only with Group Code OA)): Failure to follow the prior payer's coverage rules.

CO-71 FAQ

What does CARC 23 do that CO-71 did not?

CARC 23 captures the full effect of prior payer processing, both payments and adjustments, and is limited to the OA group code. CO-71 only referred to the primary payer's amount.

Is the primary payer amount a write-off?

No. It reflects money already paid or adjusted by the primary payer. It reduces what the secondary pays but should not be written off as a loss.

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