Before you start

A residence permit or validated visa
Proof of stable residence in France
An employment contract or proof of activity, for the fastest route
A French RIB, for reimbursements

Step-by-step

1
Start the social security registration in your first week
If you are employed, your employer initiates it, but the process is slow and you should track it rather than assume it is moving. The number is what everything else hangs off. Expect months rather than weeks and do not read the delay as a sign something has gone wrong.
Via employerWho: You and your employerWeek 1
2
Keep every feuille de soins until the card actually works
Until the carte Vitale arrives you pay in full and the practitioner gives you a paper claim form. Keep all of them — once your file is active they are reimbursed retroactively, and people routinely lose several hundred euros by discarding paperwork that appeared to be going nowhere.
In personWho: You
3
Declare a médecin traitant in your first weeks and ask people rather than directories
Naming a family doctor with the fund raises your reimbursement rate permanently and is the gateway to specialists. Practices in and around Grenoble close their lists, and a personal referral from a colleague or neighbour opens doors a directory search does not.
In personWho: YouWeek 1–4
4
Take the employer mutuelle, and check what it says about mountain sports
The state reimburses most but not all of a consultation and covers dental and optical care poorly, and employers must offer a scheme and fund at least half of it. Here there is a second question: what the mutuelle, or a separate carte neige or club licence, covers for search, rescue and repatriation off a mountain. Read that section rather than assuming it is included.
Via employerWho: You
5
Create an Ameli account as soon as you have a number
The online account is where reimbursements, your card status and the attestation de droits live. That attestation is another document you will be asked for repeatedly, by employers, schools and insurers.
OnlineWho: You
6
Learn the three out-of-hours numbers before you need them
15 is for genuine emergencies, including anything in the mountains. 116 117 is the out-of-hours GP access line for everything that is not one. Pharmacies run a duty rota with the on-call pharmacy posted in the window and online.
OnlineWho: You

Documents you’ll need

Residence permit or validated visa
Birth certificate with a sworn translation, frequently required
Employment contract or proof of activity
Justificatif de domicile
RIB for reimbursements

Things most newcomers don’t know

Your carte Vitale is not a mountain rescue policy, and this is the city where that distinction gets expensive.

Health insurance covers treatment. Getting you off a piste, out of a couloir or down from a ridge is a separate operation, and whether it is chargeable depends on where it happened and who performed it — rescue inside a ski area is generally billable to the person rescued, and the sums are not trivial. Almost every arrival here will end up on a mountain within a season. Check what your mutuelle, your ski pass insurance, your club licence or a dedicated carte neige actually covers before the first trip, not after.

Source: community-reported

Not declaring a médecin traitant costs you on every single consultation, indefinitely.

The reimbursement rate inside the coordinated care pathway is substantially higher than outside it, and you are outside it until you have formally named a family doctor with the fund. That is a permanent penalty rather than a one-off, and it applies from your first visit. Treating it as a first-month task rather than a first-illness task is the difference, particularly where practice lists are closed.

Source: l'Assurance Maladie

Keep every paper claim form from your first months — they are literally money.

Before the carte Vitale arrives you pay in full and receive a feuille de soins to submit on paper. Once your file is active those claims are reimbursed retroactively, sometimes many months later. New arrivals discard them because nothing appears to be happening, and then cannot reconstruct several hundred euros of legitimate reimbursement they were entitled to.

Source: l'Assurance Maladie

A translated birth certificate is the single most common reason a registration file sits still.

French social security registration frequently requires a full birth certificate, sometimes recently issued, translated by a court-approved sworn translator. Obtaining one from another country takes weeks, and the requirement rarely surfaces until the file is already open and waiting. Start it before you leave rather than when the caisse asks for it.

Source: l'Assurance Maladie

Common mistakes to avoid

Assuming the carte Vitale covers being rescued and evacuated off a mountain.
Discarding paper claim forms before your social security file is active.
Leaving the search for a médecin traitant until you are actually ill.
Arriving without a translated birth certificate and stalling registration for weeks.
Declining the employer mutuelle without understanding what the state does not cover.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.