CARC 20 Active

OA-20: Liability Carrier Responsible

TL;DR

Adjustment in a COB or secondary payer context. Review the coordination of benefits details to determine the responsible party.

Action
Resubmit
Who Pays
Depends
Appeal
Yes
Patient Impact
Indirect
Disclaimer
This content is for informational purposes only and does not constitute professional billing advice. Always verify information against your payer contracts and current coding guidelines. Consult a certified billing specialist for specific claim issues.

What Does OA-20 Mean?

With OA (Other Adjustments), CARC 20 typically appears in a coordination of benefits (COB) context. Health plan redirects claim to liability carrier in coordination of benefits. The financial responsibility depends on the specific arrangement between payers — review the primary payer's EOB and the COB terms to determine the correct course of action.

CARC 20 indicates liability carrier responsible. The payer determined that the service or a portion of it does not meet coverage criteria under the patient's current plan benefits or the applicable coverage rules.

Common scenarios that trigger this adjustment include: services for an injury from an automobile accident were billed to health insurance instead of the auto liability carrier; Payer determined that a third-party liability carrier (auto, premises) is responsible for the injury; Health plan is pursuing subrogation and denying the claim pending liability determination. The group code paired with CARC 20 determines who bears the financial responsibility — CO places it on the provider as a contractual obligation, OA indicates a coordination of benefits or other payer adjustment, PR shifts it to the patient.

Common Causes

Cause Frequency
Liability redirect in COB Health plan redirects claim to liability carrier in coordination of benefits Most Common

How to Resolve

  1. Review the coordination of benefits Examine the OA-20 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. Appeal or resubmit if needed Appeal with documentation proving no liability carrier involvement.
  5. Follow up Monitor the claim status and take additional action as needed based on the COB determination.
Appeal Guide

Appeal with documentation proving no liability carrier involvement.

Common RARC Pairings

The RARC code tells you exactly what triggered the OA-20:

RARC Description
N36 Claim must meet primary payer requirements Submit to liability carrier →

How to Prevent OA-20

Also Filed As

The same CARC 20 may appear with different Group Codes:

CO-20 PR-20

Related Denial Codes

OA-19 — Workers' Compensation Claim OA-21 — No-Fault Carrier Responsible OA-22 — Coordination of Benefits - Another Payer May Cover OA-23 — Prior Payer Adjudication Impact OA-26 — Expenses Incurred Prior to Coverage

Sources

  1. https://x12.org/codes/claim-adjustment-reason-codes
  2. https://revenuecyclemgmt.com/claim-adjustment-reason-codes/
  3. https://www.rivethealth.com/blog/carcs-rarcs-claim-adjustment-remittance-advice-codes
  4. Codes maintained by X12. Visit x12.org for official definitions.