CARC Code 1
The amount applied to the patient deductible.
What this denial means
When you see CARC code 1 on your Explanation of Benefits (EOB), it means your insurer has denied the claim with the following reason: the amount applied to the patient deductible.
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 deductible cost-share — you likely owe this amount. If your deductible has already been met, check the member portal and dispute in writing.
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.