OA-118: ESRD Network Support Adjustment

What Does OA-118 Mean?

OA-118 indicates the ESRD network support adjustment is being applied outside the standard contractual framework, typically in coordination of benefits scenarios where the assessment allocation spans multiple payers. The financial impact depends on how the ESRD assessment is split between payers.

CARC 118 appears on remittances for End-Stage Renal Disease (ESRD) services when the payer deducts the ESRD network support assessment from the provider's payment. ESRD Networks are regional organizations established under federal mandate to improve the quality of care for patients with kidney failure. The assessment is a standard reduction applied to dialysis facility and renal service claims to fund these network operations.

This adjustment is not a denial in the traditional sense — it is a predictable, contractual deduction that providers participating in ESRD care should expect on every qualifying claim. The amount is typically a small percentage of the total payment and is consistent across claims for the same service type. Providers who are new to ESRD billing may be surprised by this code, but experienced dialysis facilities account for it in their revenue projections.

The code most commonly appears with Group Code CO, confirming it as a contractual write-off that cannot be billed to the patient. Occasionally it may appear with OA in multi-payer scenarios. While the standard assessment is not appealable, providers should verify the deduction amount matches the current network support rate. If the amount appears incorrect or is applied to services that should not carry the assessment, contact the payer for clarification.

How to Resolve

Verify the ESRD network support assessment amount is correct, then write off as a standard contractual adjustment.

1. Review the multi-payer allocation Determine how the ESRD network support assessment is allocated between the primary and secondary payers.
2. Verify the total assessment is correct Ensure the combined assessment across all payers matches the expected rate and is not duplicated.

How to Prevent OA-118

• Coordinate ESRD billing across payers to ensure the network support assessment is applied correctly and not duplicated

Also Filed As

The same CARC 118 may appear with different Group Codes:

Related Denial Codes