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CO-104 Denial Code: Managed Care Withholding

CO-104 means the payer withheld part of the payment under a managed care arrangement. The withheld amount is set aside under your contract's risk-sharing terms and may be returned later, in whole or part, depending on the plan's settlement and performance results.

Code: CO-104 (CARC 104)
Status: Active In use since January 1, 1995.
Code set: Claim Adjustment Reason Codes (CARC)
Group codes: CO (Contractual Obligation): The withheld amount is a contractual item between provider and payer. It is not billable to the patient, even if it is never returned.
Official description: Managed care withholding.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What CO-104 means

CARC 104 is managed care withholding. Under some managed care contracts, the payer holds back a portion of each payment as a risk-sharing reserve. At the end of the contract period the payer reconciles results, such as medical costs, utilization, or quality targets, and decides how much of the withheld money to return.

On the ERA, the withheld portion appears as CO-104. The rest of the claim is paid normally, and the patient’s cost-sharing is not affected.

Example: a contract includes a withhold on fee-for-service payments. On each paid claim, the ERA shows the withhold as CO-104. After the plan year, the payer issues a settlement that returns part of the total withheld, based on the contract’s terms.

Common causes

Your contract includes a withhold provision, and the payer is applying it as written.
A contract amendment added or changed the withhold rate.
The payer applied a withhold to a product line or provider that the contract does not cover.
A network or IPA arrangement passes a withhold down to participating practices.

How to fix it

Confirm the contract terms. Check the withhold rate, the products it applies to, and the settlement schedule.
Verify the calculation on a sample of claims. If the withheld amount is higher than the contract allows, or applied to excluded plans, contact the payer for reprocessing.
Post withholds to a trackable account so the total can be reconciled against the settlement statement.
Review the settlement when it arrives. Ask the payer for its calculation if the amount returned looks low.
Do not bill the patient or send a corrected claim. Nothing on the claim caused the withhold.

How to prevent problems with CO-104

Summarize withhold terms for every managed care contract, including settlement timing and dispute rights.
Build expected withhold percentages into your contract modeling so revenue forecasts are realistic.
Monitor withholds by payer and product with an ERA Analyzer so you can spot rate changes or misapplied withholds early.
Keep settlement letters and supporting reports on file for audit and negotiation.
Report CO-104 separately from denials. It is a contract mechanism, not a claim problem. See how to read CARC and RARC codes.

Remark codes that may appear with CO-104

N552 (Payment adjusted to reverse a previous withhold/bonus amount.): Appears when a later payment reverses or releases a previous withhold.

CO-245 (Provider performance program withhold.): Provider performance program withhold, a withhold tied specifically to quality or performance measures.
CO-161 (Provider performance bonus): Provider performance bonus, which can be the positive side of the same arrangement.
CO-143 (Portion of payment deferred.): Portion of payment deferred, a timing adjustment rather than a risk withhold.
OA-24 (Charges are covered under a capitation agreement/managed care plan.): Charges covered under a capitation agreement, another managed care payment model.

CO-104 FAQ

Will I get the CO-104 money back?

It depends on your contract. Many withhold arrangements return some or all of the amount at settlement if targets are met, but some keep it to cover plan losses. Your contract sets the terms.

Can I bill the patient for a managed care withhold?

No. The withhold is between you and the payer. Patient cost-sharing is calculated separately and is not affected.

How should I post CO-104?

Post it to a withhold receivable or a dedicated adjustment code, not as a contractual write-off, so you can reconcile it when the settlement arrives.

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