Before appealing: understand why it was refused
A reimbursement refusal always has a precise reason. First step: check your reimbursement statement on ameli.fr. Every refusal is coded. The most common codes: "outside the coordinated care pathway" (specialist consultation without a GP referral), "non-conventional practitioner", "non-reimbursable procedure", or "prescription time limit exceeded".
When the refusal is justified — and when it isn't
Some refusals are legitimate: if you saw a specialist without a referral when it wasn't urgent, a reduced reimbursement is normal. On the other hand, a refusal can be challenged if you were in an emergency situation, if your GP was absent or unavailable, if you saw a specialist with direct access (ophthalmologist, gynaecologist, psychiatrist, dentist), or if you've just arrived in France and haven't yet declared a GP.
How to write your administrative appeal
Send a letter to your CPAM within 2 months of the refusal notice. Explain the concrete circumstances: why you saw that particular doctor, why you didn't go through your GP, and what justifies normal reimbursement. Attach the prescription if you have one and any document proving the urgency or exceptional nature of the situation.
The Commission de Recours Amiable: the next step
If your administrative appeal is rejected, refer the matter to CPAM's Commission de Recours Amiable (CRA) within 2 months. The CRA is an internal body that reviews your file. It has 2 months to reach a decision. If it upholds the refusal, you have a further 2 months to take the case to the social affairs court.
Avoiding this problem in future
The simplest solution: declare a GP on ameli.fr if you haven't done so yet, and get into the habit of going through them before any specialist. If your GP is unavailable in an emergency, note the date and time of your attempt to reach them — this will be a strong argument in any future appeal.