OA-173: Service Not Prescribed by a Physician

What Does OA-173 Mean?

When paired with Group Code OA, CARC 173 (Service Not Prescribed by a Physician) 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 173 is used when the payer determines that service not prescribed by a physician. The claim could not be processed as submitted because required information was absent, incomplete, or did not meet the payer's submission standards.

Common scenarios that trigger this adjustment include: the service or equipment requires a physician's order or prescription to be covered, but no order was on file or referenced on the claim at the time of submission; The order was written by a non-physician practitioner (NP, PA) but the payer requires a physician's order for this specific service or equipment; The physician's prescription or order has expired and is no longer valid for the date of service. The group code paired with CARC 173 determines who bears the financial responsibility — CO places it on the provider as a contractual obligation, PR shifts it to the patient, OA indicates a coordination of benefits or other payer adjustment.

How to Resolve

1. Review the coordination of benefits Examine the OA-173 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 If the OA adjustment appears incorrect based on the COB arrangement, submit an appeal or corrected claim with the appropriate documentation.
5. Follow up Monitor the claim status and take additional action as needed based on the COB determination.

How to Prevent OA-173

• Maintain accurate coordination of benefits information
• Verify secondary payer requirements before claim submission

Also Filed As

The same CARC 173 may appear with different Group Codes:

Related Denial Codes