EOB — Medicare Advantage. Plan: Health First MA. Member: MEM-13980. Date of Service: 2026-04-15. Provider: Sunrise Family Medicine (NPI 0000000002). Service: Office visit, established patient, level 3 (CPT 99213). Billed: $145. Allowed: $0. Paid: $0. CARC 18 — Exact duplicate claim/service. This is an exact duplicate of claim 26-0420-2255 already processed and paid in full at the in-network rate on 2026-04-22. Original payment: $98.45.
No appeal needed or appropriate. Direct member to confirm the original claim was paid via Member Services if uncertain. Provider should void or correct the duplicate submission with their billing team. If there's any concern about the original payment amount, request the itemized claim history from Member Services rather than appealing this duplicate denial.
CARC 18 with explicit reference to a prior paid claim is the canonical non-appealable Duplicate scenario. Filing an appeal would be inappropriate — there's no underlying coverage dispute, just a billing duplication. The right CSR triage refuses to recommend appeal.
Per-scenario model output is captured during a leaderboard Run all. Trigger a run from the leaderboard to see each variant’s output side-by-side with the ground truth here.
To run this scenario through the live cockpit, copy the EOB above into the cockpit and watch the streamed triage in context.