Remark Code
IAO
Remark Code
RA835: N122
CO — Contractual Obligations
Remark Code IAO — PROCEDURE IS AN ADD-ON CODE AND MUST BE BILLED WITH THE PRIMARY PROCEDURE.
Official Description
PROCEDURE IS AN ADD-ON CODE AND MUST BE BILLED WITH THE PRIMARY PROCEDURE.
🗂️ RA835 Mapping & EDI Details
The table below shows how Remark Code IAO maps to the 835 Healthcare Claim Payment/Advice transaction.
| Field | Value |
|---|---|
| Remark Code | IAO |
| Remark Description | PROCEDURE IS AN ADD-ON CODE AND MUST BE BILLED WITH THE PRIMARY PROCEDURE. |
| RA835 Remark Code | N122 |
| RA835 Remark Description | Add-on code cannot be billed by itself. |
| Adjustment Group Code | CO Contractual Obligations |
| Adjustment Reason Code | 97 |
| Adjustment Reason Description | The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated. Usage: Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present. |
📋 Usage Note
Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present.
⚠️ Common Causes
Remark Code IAO typically appears on an Explanation of Benefits (EOB) or remittance advice for the following reasons:
- 1The submitted diagnosis code is not consistent with the provider's specialty or type.
- 2Missing, incomplete, or invalid secondary/other diagnosis codes on the claim.
- 3The procedure billed does not align with the diagnosis codes provided.
- 4Incorrect or outdated ICD code used for the given service date.
- 5Payer policy requires additional documentation supporting the diagnosis.
✅ Resolution Steps
Follow these steps to resolve a claim denied or adjusted with Remark Code IAO:
- 1Review the original claim and verify all diagnosis codes are accurate and current (ICD-10-CM).
- 2Confirm the diagnosis is appropriate for your provider type and specialty.
- 3Check for any missing or incomplete secondary diagnosis fields and resubmit corrected data.
- 4Consult the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF) if present for payer-specific guidance.
- 5If the denial appears incorrect, gather supporting clinical documentation and file an appeal with the payer within the timely filing window.
- 6Contact the payer's provider relations line for clarification if the reason remains unclear after review.
🏷️ Adjustment Group: CO
This remark code is associated with adjustment group code CO — Contractual Obligations.
CO
Contractual
Payer contractual write-off; not billable to patient.
PR
Patient Resp.
Deductible, copay, or coinsurance owed by patient.
OA
Other Adj.
Adjustments not covered by CO or PR groups.
The active group for this code is highlighted: CO — Contractual Obligations
❓ Frequently Asked Questions
What does Remark Code IAO mean?
PROCEDURE IS AN ADD-ON CODE AND MUST BE BILLED WITH THE PRIMARY PROCEDURE. In 835 EDI transactions, this maps to RA835 remark code N122: Add-on code cannot be billed by itself.
Is Remark Code IAO a denial or informational code?
Remark codes can be either informational or indicate a denial/adjustment. This code is associated with adjustment group CO (Contractual Obligations). Always check the accompanying CARC (Claim Adjustment Reason Code) on the remittance for the full picture.
Can I appeal a claim with Remark Code IAO?
Yes. If you believe the remark was applied incorrectly, you may file an appeal with supporting clinical documentation. Review the payer's appeal guidelines and ensure you file within the timely filing deadline specified in your contract.
What is the difference between a Remark Code and a Denial Code?
A Denial Code (CARC — Claim Adjustment Reason Code) explains why a payment was reduced or denied. A Remark Code provides supplemental information to clarify the adjustment — they often appear together on the same remittance line.
Where do I find Remark Code IAO on the remittance?
On an 835 ERA, look in loop 2110 (Service Payment Information) under the RMK segment. On a paper EOB it typically appears in the "Remark" or "Message" column alongside the service line.
Disclaimer: The information on this page is provided for educational purposes only and reflects general industry guidance. Always verify codes and policies directly with the payer or consult a certified medical billing professional for claims-specific advice.