CO-204: Service is not covered under the patient's plan
CO-204 means the payer's adjudication system says the service isn't a covered benefit on your specific plan. That can be a true exclusion (e.g., cosmetic surgery) or a misread of your plan's Summary of Benefits and Coverage (SBC).
Why this denial happens
- The service is genuinely excluded - read your SBC and Evidence of Coverage to confirm.
- The payer applied the wrong plan or product on file (common after employer plan changes).
- The service is covered but under a different benefit category (e.g., 'durable medical equipment' instead of 'office visit').
How to fix or appeal CO-204
- Pull your current Summary of Benefits and Coverage and search for the service by name.
- If the SBC says the service is covered, file an appeal and attach the relevant SBC page.
- If the exclusion is genuine, ask whether your employer offers an exception process or whether a covered alternative exists.
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