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CO-139 Denial Code: Subscriber Employed by Provider

CO-139 means a contracted funding agreement applies because the subscriber is employed by the provider of services. The provider's own employee health plan covers the patient, and the payment follows a funding arrangement between the plan and the provider. X12 limits it to group CO.

Quick facts

Code
CO-139 (CARC 139)
Status
Active In use since June 30, 1999; last modified May 1, 2018.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The only group allowed. The adjustment is part of the funding arrangement between the provider (as employer) and the plan, and is not billed to the patient.
Official description
Contracted funding agreement - Subscriber is employed by the provider of services. Use only with Group Code CO.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-139 means

CARC 139 reads contracted funding agreement - subscriber is employed by the provider of services, and it is used only with group code CO. It covers a specific situation: the patient’s health coverage comes from the same organization that provided the care. A hospital or health system that self-funds its employee health plan is the typical case.

In that arrangement, the plan and the provider are, in a sense, the same organization. They often agree on special funding terms for employee care, such as internal rates or direct funding, and the plan’s administrator reports the difference from billed charges as CO-139.

Example: a hospital employee has surgery at the hospital. The hospital’s self-funded plan, administered by a third party, pays under the internal funding agreement. The ERA shows CO-139 for the adjustment and PR amounts for the employee’s cost-sharing.

Common causes

  • A self-funded employer plan that pays the employer’s own facilities at internal rates.
  • A funding agreement that moves money between the plan and the provider outside the normal claim payment.
  • Employee dependents treated at the employer’s facilities.
  • A payer applying CO-139 to a patient who is not actually an employee, which is an error.

How to fix it

  1. Confirm the relationship. Verify the subscriber is employed by your organization and covered under its plan.
  2. Check the funding agreement for the rate or method that should apply.
  3. If the adjustment is correct, post it as a contractual adjustment. No further action is needed.
  4. If the subscriber is not your employee, contact the payer and ask it to reprocess under the correct contract.
  5. Bill only true patient responsibility reported under PR.

How to prevent problems with CO-139

  • Share the employee plan’s funding terms with patient accounting so these claims are posted correctly.
  • Keep a separate payer or plan code for the employee health plan in your billing system.
  • Review CO-139 adjustments periodically with finance and human resources to confirm they match the agreement.
  • Keep internal funding adjustments out of denial reports. See how to read CARC and RARC codes.
  • CO-308 (Payment is adjusted due to contracted funding agreement between the payer and provider.): A general contracted funding agreement between payer and provider, without the employment link.
  • CO-131 (Claim specific negotiated discount.): Claim-specific negotiated discount.
  • CO-45 (Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement.): Standard fee schedule or contracted rate reduction.
  • OA-24 (Charges are covered under a capitation agreement/managed care plan.): Charges covered under a capitation agreement or managed care plan.

CO-139 FAQ

When does CO-139 appear?

Typically when a hospital or health system treats its own employees or their dependents under the organization's self-funded health plan, and the plan pays under a special internal arrangement.

Is CO-139 a denial?

No. It is an adjustment reflecting how the employer plan and the provider have agreed to fund care for employees.

Can the employee be billed for the CO-139 amount?

No. The CO group means the provider absorbs it. The employee still owes any deductible, coinsurance, or co-payment reported under PR.