OA-231: Mutually Exclusive Procedures on Same Day

What Does OA-231 Mean?

OA-231 is used when the mutually exclusive procedure determination involves complex multi-party coordination or when the adjustment does not fall clearly to provider or patient responsibility. This is less common than CO-231.

CARC 231 fires when the payer's coding edits determine that two procedures billed for the same date of service are mutually exclusive. Mutually exclusive procedures are those that, by their clinical nature, cannot reasonably be performed on the same patient on the same day or in the same setting. This is different from bundling (where one procedure is a component of another) — mutually exclusive means the procedures logically conflict.

The most common trigger is billing two procedure codes that appear as a mutually exclusive pair in the NCCI Procedure-to-Procedure (PTP) edits or the payer's internal coding rules. Sometimes the procedures were never both performed and the denial is simply a coding error. Other times, both procedures were legitimately performed but the coding does not reflect the clinical distinction that justified performing them concurrently.

This code typically appears with Group Code CO, meaning the provider absorbs the cost and cannot bill the patient. In some cases OA is used when the adjustment involves coordination between multiple parties. The denial applies to the lower-paid procedure in the pair, while the higher-paid procedure is usually reimbursed.

How to Resolve

Verify whether both procedures were actually performed, check NCCI edits for the code pair, and either correct the coding or appeal with clinical justification.

1. Determine the responsible party Review the denial details to understand why OA was used instead of CO, and identify whether multi-provider coordination or other factors are involved.
2. Coordinate with involved parties If multiple providers performed the conflicting procedures, coordinate with the other provider to determine which claim should be adjusted and how to resolve the conflict.

Common RARC Pairings

The RARC code tells you exactly what triggered the OA-231:

How to Prevent OA-231

• Establish communication protocols between providers performing procedures on the same patient on the same day
• Verify with the payer which party is responsible for resolving OA-flagged mutually exclusive denials

Also Filed As

The same CARC 231 may appear with different Group Codes:

Related Denial Codes