OA-159: Service Provided as Result of Terrorism

What Does OA-159 Mean?

OA-159 appears when the payer uses an 'other adjustment' designation to shift the claim away from the commercial plan. This typically occurs in coordination of benefits scenarios where the payer has identified a government or federal program as the responsible party for terrorism-related care. The OA group code signals that neither the provider nor the patient should absorb the cost — the claim should be redirected to the appropriate program.

When CARC 159 appears on a remittance, the payer is telling you that the billed service or procedure was provided in connection with an act of terrorism and therefore falls outside the scope of the patient's commercial health plan coverage. The payer has determined — based on the claim data, diagnosis codes, or external cause codes — that the care was rendered as a direct result of a terrorism incident, and standard plan benefits do not apply.

This code is uncommon in everyday billing. It typically surfaces in the aftermath of a federally declared terrorism event when providers are treating patients injured in the incident. The denial is not necessarily a rejection of the medical necessity of the service — it is a coverage determination indicating that a different funding source (usually a federal program) should bear the cost. Programs such as FEMA disaster relief, the Public Readiness and Emergency Preparedness (PREP) Act, or state-level victim compensation funds may be the appropriate payer.

The most actionable scenario for billing staff involves a coding error: if a claim was inadvertently coded with ICD-10 external cause codes from the Y38 terrorism series when the service was actually unrelated to any terrorism event, the payer may automatically apply CARC 159. In this case, correcting the external cause codes and resubmitting with clear clinical documentation is the path to resolution. Note that some state Medicaid programs (e.g., Massachusetts) explicitly reject encounters submitted with CARC 159, so be aware of payer-specific handling rules.

Common Causes

How to Resolve

Determine whether the service was genuinely terrorism-related or miscoded, then either redirect the claim to the correct federal program or correct the coding and resubmit.

1. Identify the responsible government program Based on the terrorism event and the patient's situation, determine which federal or state program should cover the service (FEMA, PREP Act, state victim compensation fund).
2. Submit to the correct program Prepare and submit the claim to the identified government program with all required documentation, including proof of the terrorism connection and medical necessity.
3. Request reprocessing if OA was applied in error If the service was not terrorism-related and the OA adjustment was made in error, contact the payer with corrected documentation and request the claim be reprocessed.

How to Prevent OA-159

• Identify terrorism-related services during patient intake and route claims to the correct program from the start
• Maintain an updated list of federal programs that cover terrorism-related medical expenses
• Coordinate with case management to determine the appropriate payer before services are rendered

General Prevention

• Identify terrorism-related services early and route claims to the correct federal program from the start rather than submitting to the commercial payer
• Maintain a list of active federal programs covering terrorism-related medical expenses and their claim submission requirements
• Coordinate with case managers to determine the appropriate payer for terrorism-related care before services are rendered

Also Filed As

The same CARC 159 may appear with different Group Codes:

Related Denial Codes