CARC Code 2
The amount applied to patient coinsurance.
What this denial means
When you see CARC code 2 on your Explanation of Benefits (EOB), it means your insurer has denied the claim with the following reason: the amount applied to patient coinsurance.
This code is one of the most common denial reasons in the CARC system and appears across both employer-sponsored and ACA marketplace plans. How you respond depends on whether the denial is a patient-side or provider-side issue.
Can you appeal this?
This is typically a provider billing matter. This is a standard coinsurance cost-share. You owe this amount unless the percentage applied is incorrect — verify against your Summary of Benefits and Coverage.
Start by contacting your provider's billing office. In many cases you may owe nothing — the adjustment is between your provider and the insurer. If you believe the denial was applied incorrectly, your provider can submit a corrected claim.
Related reading
Not legal or medical advice. Rebuttal is a document drafting tool, not a law firm. Review your letter before submitting and consult a licensed professional for legal questions specific to your plan.