OA-105: Tax Withholding Amount

What Does OA-105 Mean?

When paired with Group Code OA, CARC 105 (Tax Withholding Amount) is processed as an adjustment outside the standard CO/PR classifications. This typically occurs in secondary payer or coordination of benefits scenarios. Review the remittance details and the COB arrangement to determine financial responsibility and appropriate next steps.

CARC 105 appears on a remittance when the payer applies an adjustment for tax withholding amount. Review the group code and any accompanying RARC codes to understand the full context of this adjustment.

Common scenarios that trigger this adjustment include: the payer is required to withhold federal income taxes from provider payments per IRS backup withholding requirements, typically when the provider has not furnished a correct TIN; State tax regulations require the payer to withhold state taxes from provider payments for providers in certain jurisdictions; An IRS levy has been placed on the provider's payments, requiring the payer to withhold a specified percentage and remit it to the IRS. The group code paired with CARC 105 determines who bears the financial responsibility — OA indicates a coordination of benefits or other payer adjustment, CO places it on the provider as a contractual obligation, PR shifts it to the patient.

Common Causes

How to Resolve

1. Review the coordination of benefits Examine the OA-105 adjustment to understand how it fits within the primary/secondary payer relationship or other multi-payer context.
2. Verify primary payer adjudication Review the primary payer's EOB to understand the basis for the secondary payer's OA adjustment.
3. Determine the responsible party Based on the COB review, identify whether the adjustment should be absorbed, billed to another payer, or if additional documentation is needed.
4. Follow up Monitor the claim status and take additional action as needed based on the COB determination.

Common RARC Pairings

The RARC code tells you exactly what triggered the OA-105:

How to Prevent OA-105

• Ensure the provider's TIN is correct and current with all payers
• Submit W-9 forms proactively when enrolling with new payers or when TIN changes
• Maintain current tax compliance to avoid IRS levies on payments
• Respond promptly to payer or IRS notices about TIN discrepancies
• Reconcile tax withholding amounts against payments received for accurate tax reporting

Also Filed As

The same CARC 105 may appear with different Group Codes:

Related Denial Codes