OA-158: Service Provided Outside the United States

What Does OA-158 Mean?

OA-158 is uncommon and may appear when the international service adjustment is informational. The resolution approach depends on whether the service was truly international or a billing error.

CARC 158 appears on your remittance when the payer has determined that the medical service or procedure was provided at a location outside the United States. Most domestic health insurance plans exclude or limit coverage for services rendered internationally, and CARC 158 is the denial code that enforces that exclusion.

The most common trigger in routine billing is a billing error — specifically an incorrect Place of Service code or provider address on the claim that indicates an international location. This can happen with telemedicine services, border-area providers, or when claims processing systems misinterpret a provider's address. Providers in U.S. territories (Puerto Rico, Guam, U.S. Virgin Islands, American Samoa) may also encounter this denial if the payer's system incorrectly classifies the territory as a foreign country.

When the service was genuinely provided outside the U.S., the resolution depends on the group code. Under CO, the provider absorbs the denial — this typically happens when the payer's contract excludes international services as a blanket provision. Under PR, the patient is responsible — common when the patient chose to seek care abroad and the plan assigns that cost to the patient. Some plans include emergency care exceptions for international services, so if the patient received emergency treatment while traveling, check whether the plan has a provision that waives the international exclusion for emergencies. Supplemental travel health insurance may also provide coverage.

How to Resolve

Determine whether the denial is due to a billing error or a genuine international service, then either correct the claim or pursue the appropriate resolution based on the group code.

1. Review the denial details Check the ERA for specific information about the international service determination.
2. Follow the appropriate resolution Verify whether the service was domestic or international, then follow the CO-158 or PR-158 resolution path as appropriate.

How to Prevent OA-158

• Follow the same Place of Service verification practices as for CO-158 and PR-158 denials

Also Filed As

The same CARC 158 may appear with different Group Codes:

Related Denial Codes