CARC 90 Active

OA-90: Ingredient Cost Adjustment

TL;DR

Adjustment in a COB or secondary payer context. Review the coordination of benefits details to determine the responsible party.

Action
Review & Decide
Who Pays
Depends
Appeal
No
Patient Impact
Indirect
Disclaimer
This content is for informational purposes only and does not constitute professional billing advice. Always verify information against your payer contracts and current coding guidelines. Consult a certified billing specialist for specific claim issues.

What Does OA-90 Mean?

When paired with Group Code OA, CARC 90 (Ingredient Cost Adjustment) 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 90 means the payer adjusted the payment based on ingredient cost adjustment. The reimbursement was calculated using the payer's fee schedule, contracted rate, or regulatory payment methodology rather than the billed charge.

Common scenarios that trigger this adjustment include: the pharmacy or provider billed an ingredient cost higher than the payer's MAC pricing list, and the payer adjusted the payment down to the MAC rate; The billed ingredient cost was based on a different pricing benchmark than the payer uses, such as AWP vs. ASP (Average Sales Price), resulting in a downward adjustment; A generic equivalent is available at a lower ingredient cost, and the payer adjusted the payment to the generic pricing level per formulary rules. The group code paired with CARC 90 determines who bears the financial responsibility — CO places it on the provider as a contractual obligation, OA indicates a coordination of benefits or other payer adjustment, PR shifts it to the patient.

How to Resolve

  1. Review the coordination of benefits Examine the OA-90 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.
Do Not Appeal This Code

Ingredient Cost Adjustment grouped under OA is an Other Adjustment that doesn't fall into the standard contractual write-off or patient responsibility categories. Whether action is needed depends on the specific reason — review any accompanying RARC codes and payer guidance to decide whether this is a final adjustment to accept or an issue to resolve through resubmission.

How to Prevent OA-90

Also Filed As

The same CARC 90 may appear with different Group Codes:

CO-90 PR-90

Related Denial Codes

OA-74 — Indirect Medical Education Adjustment OA-75 — Direct Medical Education Adjustment OA-76 — Disproportionate Share Adjustment OA-85 — Patient Interest Adjustment OA-89 — Professional Fees Removed from Charges

Sources

  1. https://www.cms.gov/medicare/payment/part-b-drugs/average-sales-price
  2. https://www.aapc.com/resources/claim-adjustment-reason-code-carc
  3. https://www.mdclarity.com/denial-code/90
  4. Codes maintained by X12. Visit x12.org for official definitions.