CARC Code 204
This service is not covered under your current benefit plan.
What this denial means
When you see CARC code 204 on your Explanation of Benefits (EOB), it means your insurer has denied the claim with the following reason: this service is not covered under your current benefit plan.
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?
Yes — this denial is patient-appealable. Argue the service is within covered benefits (cite Summary of Benefits / Evidence of Coverage) or qualifies via medical-necessity or an exception; request the specific plan provision relied on and invoke external review where coverage turns on medical judgment.
Applicable federal regulations:
ERISA plans (employer-sponsored)
- ERISA § 503
- 29 CFR § 2560.503-1(h)
ACA plans (marketplace / individual)
- PHS Act § 2719
- 45 CFR § 147.136(b)
- 45 CFR § 147.136(c)
- 45 CFR § 147.136(d)
Your insurer's legal team is bound by these regulations. An appeal letter that cites them directly demands a specific, documented response.
What to include in your appeal
Gather as many of these supporting documents as apply to your denial:
- –Explanation of Benefits (EOB)
- –Doctor's letter of medical necessity
- –Clinical notes and records from your provider
- –Prior authorization record (if applicable)
- –Summary of Benefits and Coverage (SBC)
See our submission guide for full instructions on each document and how to submit your appeal.
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.