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CO-W9 Denial Code (Deactivated): Outpatient Facility Fee

CO-W9 meant the service was not paid under the jurisdiction's allowed outpatient facility fee schedule. X12 deactivated it and its notes direct payers to code P20.

X12 deactivated CARCW9 on July 1, 2014. Payers should no longer use it on new remittances, but it can still appear on older ERAs, corrected claims, and appeals.

Code: CO-W9 (CARC W9)
Status: Deactivated StoppedJuly 1, 2014 (in use since June 2, 2013).
Code set: Claim Adjustment Reason Codes (CARC)
Group codes: CO (Contractual Obligation): The unpaid facility amount was a provider adjustment.
Official description: Service not paid under jurisdiction allowed outpatient facility fee schedule.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What CO-W9 meant

CARC W9 applied to facility bills. States that regulate workers’ compensation payment often have a separate fee schedule for outpatient facility charges. If a service was not payable under that schedule, the carrier denied the facility portion with this code. The professional component, billed separately, might still be paid.

What replaced it

X12’s note says to use code P20. CO-P20 now carries this meaning. Other workers’ compensation facility adjustments may appear as CO-P12 for fee schedule reductions or CO-P13 for regulatory or policy-based reductions.

If you still see CO-W9

Older facility remittances may carry it. Review the state’s outpatient facility fee schedule and billing rules for that date of service. Check whether the service should have been billed on a professional claim instead, or with a different revenue code or setting. Rebill if the claim was set up incorrectly; otherwise, write off the unpaid facility charge.

CO-P20 (Service not paid under jurisdiction allowed outpatient facility fee schedule.): Named replacement: service not paid under the jurisdiction's allowed outpatient facility fee schedule.
CO-P12 (Workers' compensation jurisdictional fee schedule adjustment.): Workers' compensation jurisdictional fee schedule adjustment.
CO-P13 (Payment reduced or denied based on workers' compensation jurisdictional regulations or payment policies, use only if no other code is applicable.): Reduced or denied under workers' compensation regulations or payment policies.

CO-W9 FAQ

Who received CO-W9?

Outpatient facilities, such as hospital outpatient departments and ambulatory surgery centers, billing workers' compensation or other property and casualty payers.

What is an outpatient facility fee schedule?

A jurisdiction's set of rules and amounts for paying facility charges on outpatient services. Services not covered by that schedule may not receive a facility payment.

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