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CO-25 Denial Code (Deactivated): Stop-Loss Deductible

CO-25 meant payment was denied because a stop-loss deductible had not yet been satisfied. It was a niche code tied to stop-loss arrangements, and X12 deactivated it without naming a direct successor.

X12 deactivated CARC25 on April 1, 2008. Payers should no longer use it on new remittances, but it can still appear on older ERAs, corrected claims, and appeals.

Code: CO-25 (CARC 25)
Status: Deactivated StoppedApril 1, 2008 (in use since January 1, 1995).
Code set: Claim Adjustment Reason Codes (CARC)
Group codes: CO (Contractual Obligation): The unpaid amount stayed with the provider under the arrangement that created the stop-loss threshold.
Official description: Payment denied. Your Stop loss deductible has not been met.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What CO-25 meant

CARC 25 read as a denial because “your stop-loss deductible has not been met.” Stop-loss provisions protect one party once costs pass a set threshold. Until that threshold is reached, the extra payment does not kick in. This code told the provider that the claim fell below the point where stop-loss coverage would pay.

It was aimed at providers in risk-bearing or specialized contracts, not at typical fee-for-service billing, which is part of why it saw little use.

What replaced it

X12 did not name a replacement. The closest active options depend on how the payer frames the adjustment:

CO-308 covers adjustments driven by a contracted funding agreement between payer and provider.
CO-45 is the general code for amounts that exceed the contracted arrangement.

Do not confuse this with PR-1, which is the patient’s own deductible and is billable to the patient.

If you still see CO-25

This code will mostly surface in historical remittance files or contract reconciliations. Pull the contract that contains the stop-loss clause and check how the threshold is measured, whether per claim, per member, or per contract year, and whether the claim counts toward it.

If you believe the threshold was met, send the payer your running totals and ask for reprocessing. Otherwise, post the amount as a contractual adjustment and keep tracking cumulative totals so later claims can be paid once the threshold is crossed.

CO-308 (Payment is adjusted due to contracted funding agreement between the payer and provider.): An active code for adjustments driven by a contracted funding agreement between payer and provider.
CO-45 (Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement.): The general code for amounts above the contracted or allowed arrangement.
PR-1 (Deductible Amount): The ordinary patient deductible, which is a different concept from a stop-loss deductible.

CO-25 FAQ

Is a stop-loss deductible the same as the patient's deductible?

No. A patient deductible is cost-sharing the member pays. A stop-loss deductible is a threshold in a risk or reinsurance arrangement that must be reached before extra coverage starts. CO-25 referred to the latter.

Should I bill the patient after a CO-25?

Not on the basis of this code. The CO group put the amount on the provider, and the deductible it referenced was not the member's plan deductible.

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