You have the visa or the Withdrawal Agreement card, the lease or the deeds, and a date circled for the move. Then a friend asks the question that stops the planning cold: how will you see a doctor in France, and who pays the bill. Since Brexit, a British passport no longer opens the French health system by itself. Every British resident now enters through one of two doors: the S1 form, a paper issued by Britain that moves the cost of your French care back to the British budget, or PUMA, the French universal cover that takes you in once you live here in a stable and lawful way. Choose the wrong door, register late, or leave a refusal unanswered, and you can spend months paying full price at the pharmacy while two administrations each insist the other one is responsible. This guide explains both routes in plain English, with the French terms translated at each step, the exact papers the CPAM, the local health fund, expects, and the remedies when the answer is no. The first part maps the two doors and the registration chain down to the carte Vitale, the green chip card that proves your rights at every appointment. The second part deals with refusals, double bills and long delays, and the appeals that overturn them. Residence rules for newcomers are covered in the companion guide on which long-stay visa and which carte de séjour a British newcomer needs, and the tax side of retirement is set out in the guides on declaring a British State Pension in France and the CSM levy charged to early retirees.

I. How do British residents get French healthcare after Brexit: S1 cover from Britain or French PUMA, and how do you register with CPAM?

French health cover rests on a single principle that surprises many British arrivals: one person, one legislation at a time. European coordination law says that a person is subject to the legislation of a single Member State only, and the Court of Cassation applies that rule strictly, including against French funds that try to keep collecting from someone insured elsewhere. The practical question for a British resident is therefore always the same: which state is competent for you, Britain through an S1, or France through work or residence. The answer decides where you register, what you pay, and which fund reimburses your treatment. The two routes below cover nearly every British profile, from the pensioner in the Dordogne to the remote worker in Lyon and the student in Paris.

A. How does the S1 form give a British pensioner, posted worker or frontier worker French healthcare without paying twice?

The S1 is a portable document, a standard European form, by which Britain tells France that it remains responsible for your healthcare costs even though you live on French soil. You receive treatment in France on the same terms as a French insured person, the French fund pays the professional, and Britain reimburses France behind the scenes. For the profiles it covers, it is the strongest protection available, because it removes any argument about French contributions: France cannot ask you to pay twice for the same cover. The British guidance page Healthcare for UK nationals living in France is the starting point on the British side, and the French fund that receives the form is the CPAM, the caisse primaire d’assurance maladie, the local branch of the national health insurance for your département.

Three groups of British residents are concerned in practice. The first and largest is State Pensioners: once you start drawing a UK State Pension, you apply for an S1 from NHS Overseas Healthcare Services, and each dependant in your household is documented too. The gov.uk guidance confirms that S1 holders must register the form at the local CPAM office, and it warns dependants who begin claiming their own UK State Pension that their cover as a dependant ends and they need an S1 in their own right. The second group is posted workers, employees sent temporarily by a British employer to work in France, who carry an S1 alongside the A1 certificate that keeps them under British social security during the posting; the French health insurance site ameli runs a dedicated page for posted workers and secondees explaining the registration. The third group is frontier workers, people who live in France and work across a border, who must contact HMRC National Insurance enquiries to confirm eligibility before an S1 is issued. If you recognise yourself in one of these descriptions, apply for the S1 before you need treatment, because the CPAM cannot backdate registration indefinitely and pharmacists cannot re-run months of receipts through a card that did not yet exist.

The legal force of this single-legislation rule is settled case law, and it binds the French funds. In a decision of 4 September 2025, the Second Civil Chamber of the Court of Cassation recalled, under Articles 1(l) and 3 of Regulation (EC) No 883/2004 on the coordination of social security systems, that a compulsory French scheme falls inside the material scope of the European regulation, so that affiliation follows the coordination rules and not the fund’s preference (Cass. 2e civ., 4 Sept. 2025, No 23-10.486). In an earlier ruling the same chamber applied the core of Article 11 of that regulation, under which persons to whom this Regulation applies shall be subject to the legislation of a single Member State only, and more precisely that a person pursuing an activity as an employed person in the territory of one Member State shall be subject to the legislation of that State, even if he resides in the territory of another Member State (Cass. 2e civ., 5 Jan. 2023, No 21-13.487). The lesson for an S1 holder is direct: once Britain certifies competence through the S1, a French fund cannot lawfully demand parallel French health contributions for the same period, and any double bill can be challenged on that ground, as the second part of this guide explains.

Registration itself is an administrative chain with three links, and each one should be kept in writing. First, obtain the S1 from the British side and check that every family member appears correctly, because a missing dependant is the most common cause of a child’s treatment being refused at the surgery desk. Second, file the S1 at your CPAM with proof of identity, proof of address, the residence permit or Withdrawal Agreement card, and bank details for reimbursements, and ask for a receipt showing the date of filing. Third, once the CPAM records the S1, you receive an attestation of rights, a paper certificate, then a social security number and finally the carte Vitale, the green chip card you present at each appointment so the professional is paid directly for the reimbursable part. Keep the attestation safe during the wait: it proves your rights at the pharmacy and the laboratory while the plastic card is being produced. Students and S1 holders travelling back to Britain or elsewhere in Europe should also note the gov.uk position that residents with a registered S1 can apply for a UK-issued EHIC, the European Health Insurance Card, for temporary stays, while British residents working in France on a French contract cannot use a UK-issued EHIC for their everyday French care and must use their French registration instead.

Two traps deserve emphasis because they generate most of the disputes seen in practice. The first is the gap between arrival and registration: treatment received before the S1 is recorded, or before PUMA opens where no S1 exists, is not automatically reimbursed later, so private cover for the first months is prudent rather than optional. The second is the dependant who starts work or starts drawing a pension: their status changes on that day, the old cover ends, and a new application in their own name must go in immediately, otherwise a hospital admission can fall exactly in the uncovered interval. Both traps are avoidable with dated paperwork and a calendar reminder, and both are much cheaper to prevent than to litigate.

B. Without an S1, how do you join PUMA after three months and get your carte Vitale?

PUMA, the protection universelle maladie, is the French universal health cover for people who live in France and are not already covered by work or by a coordination document such as the S1. It is the natural home of the British early retiree, the British spouse who does not work, the student who stays beyond a temporary visit, and anyone whose S1 has ended. The statute opens with a sentence worth reading in full: Toute personne travaillant ou, lorsqu’elle n’exerce pas d’activité professionnelle, résidant en France de manière stable et régulière bénéficie, en cas de maladie ou de maternité, de la prise en charge de ses frais de santé dans les conditions fixées au présent livre. (Article L. 160-1 of the Social Security Code). Three words carry the whole test: working, or otherwise resident in a stable and regular way. If you work in France on a French contract, you enter through work from day one. If you do not work, you enter through residence once stability and regularity are established.

Stability has a precise administrative meaning. The regulation provides that sont considérées comme résidant en France de manière stable les personnes qui ont leur foyer ou le lieu de leur séjour principal sur le territoire métropolitain, en Guadeloupe, en Guyane, à la Martinique, à la Réunion, à Saint-Barthélemy ou à Saint Martin (Article R. 111-2 of the Social Security Code), and the service-public.fr fact sheet What is the PUMA? together with the ameli page on universal cover confirm the practice: three months of continuous presence before the application, proved by dated evidence such as the lease, utility bills, and bank statements showing everyday life in France. Regularity means lawful presence: a Withdrawal Agreement card for protected residents, or the appropriate long-stay visa and residence permit for newcomers, as explained in the newcomer visa guide. A British resident who alternates between two countries should organise proof around the centre of everyday life, because the fund looks at where the person normally lives, not at the address printed on a single bill.

The statute also carves out profiles that do not take the standard PUMA road where they do no additional professional activity in France: L’article L. 160-1 ne s’applique pas aux personnes suivantes si elles n’exercent pas une activité professionnelle complémentaire en France : 1° Les membres du personnel diplomatique et consulaire en poste en France, les fonctionnaires d’un Etat étranger et personnes assimilées, ainsi que les membres de leur famille qui les accompagnent ; 2° Les personnes qui sont venues en France pour suivre un traitement médical ou une cure, with a further item for holders of a foreign pension without a French benefit (Article L. 160-6 of the Social Security Code). If you belong to one of these groups, do not file a standard PUMA application and wait: check the coordination route first, usually the S1, and take advice on which fund is competent before any contribution notice arrives. For everyone else, the application goes to the CPAM of the place of residence, on the dedicated form, with identity documents, the residence permit, proof of three months’ presence, and bank details. The service-public.fr page for applying to open health insurance rights lists the current filing channels, and asking for a dated receipt at the counter or keeping the online confirmation is essential, because the opening date of your rights runs from a complete file.

Once affiliated, the cover has three layers that British residents often confuse. The base layer reimburses the defined basket of care: La protection sociale contre le risque et les conséquences de la maladie prévue à l’article L. 111-2-1 comporte : 1° La couverture des frais de médecine générale et spéciale, des frais de soins et de prothèses dentaires, des frais pharmaceutiques et d’appareils, continuing through examinations, hospital stays and related items (Article L. 160-8 of the Social Security Code). Reimbursement is usually partial, around seventy per cent for an ordinary surgery visit, which is why the second layer matters: the mutuelle, a voluntary top-up insurance that pays most or all of the remainder, and which almost every long-term resident takes out. The third layer is the complémentaire santé solidaire, the means-tested public top-up, granted as of right to persons covered by Article L. 160-1: Les personnes mentionnées à l’article L. 160-1 ont droit à une protection complémentaire en matière de santé dans les conditions suivantes : 1° Sans acquitter de participation financière lorsque leurs ressources ainsi que celles des autres personnes membres du même foyer sont inférieures à un plafond déterminé par décret (Article L. 861-1 of the Social Security Code). A British resident on a modest pension should check this ceiling before paying for a private mutuelle. Finally, nominate a médecin traitant, the declared GP who coordinates referrals: without one, reimbursements for hospital consultant visits are cut, and the cut applies silently on each statement.

One cost warning belongs here for early retirees with capital income but little or no French professional earnings. Persons covered by Article L. 160-1 can owe an annual contribution, the CSM, the cotisation subsidiaire maladie, where professional income in France sits below a yearly threshold: Les personnes mentionnées à l’article L. 160-1 sont redevables d’une cotisation annuelle lorsqu’elles remplissent les conditions suivantes : 1° Leurs revenus tirés, au cours de l’année considérée, d’activités professionnelles exercées en France sont inférieurs à un seuil fixé par décret. (Article L. 380-2 of the Social Security Code). The calculation, the thresholds and the challenges are worked through in the dedicated guide on the CSM levy for British early retirees, and S1 holders are outside it for the periods Britain certifies. Knowing which side of that line you stand on avoids the shock of a four-figure notice in November.

II. What happens when CPAM says no, bills you, or leaves you waiting, and how do you challenge it?

Refusals and delays are not rare, and they are not always unlawful: sometimes the file is genuinely incomplete, sometimes the applicant knocked on the wrong door. But French funds also refuse files they should accept, bill contributions they should not bill, and leave families months without the card while treatment costs pile up. The difference between a setback and a disaster is method. This part lists the recurring blockages, the proof that unblocks each one, and the appeal ladder that turns a no into a yes with backdated effect. Throughout, one habit decides everything: keep every letter, every receipt and every screenshot, because the appeal bodies decide on papers, and the party with dated papers usually wins.

A. Why does CPAM refuse registration or charge a levy, and what proof unblocks the file?

The most frequent refusal ground is residence evidence judged too thin: a single recent utility bill, a bank account barely used, long absences in Britain that suggest the centre of life never moved. The answer is volume and spread: twelve months of overlapping traces where possible, lease and housing tax, electricity and internet, French bank movements for everyday spending, school certificates for children, and the residence permit showing lawful stay. Where the fund doubts regularity rather than stability, the Withdrawal Agreement card or the current permit plus the visa history closes the point; newcomers whose permit is still being processed should file anyway with the récépissé, the temporary receipt, and complete the file the day the card arrives rather than waiting to apply. A second classic blockage is the S1 that the CPAM says it cannot find or cannot read: produce the copy stamped by the British issuer, the proof of posting or hand delivery to the CPAM, and the delivery receipt, then ask in writing for the form to be recorded with effect from the date of the complete filing. Funds have been known to sit on European forms for months; a dated record of transmission turns that delay into a recoverable error.

Double affiliation demands are the next battleground. A British pensioner with a recorded S1 who receives a French health contribution notice, or an employee posted from Britain who is asked for French health contributions on top of British ones, faces exactly the situation the coordination regulation forbids. The case law above on the single applicable legislation is the shield, and a recent illustration shows how courts handle the mirror dispute: a person living in France and working in Switzerland asked the French fund for reimbursement of health contributions paid since 2015, the fund refused, and the litigation turned on which state was competent and which levies genuinely finance a social security branch (Cass. 2e civ., 25 Sept. 2025, No 22-24.634). The ruling rejected that particular claim on its facts, which is itself instructive: these cases are won or lost on precise proof of the competent state, the nature of each levy, and the periods concerned, never on general statements about fairness. So the practical response to a double bill is a short, documented letter: identify the S1 or A1 with its dates, attach it, cite the single-legislation rule, and ask for withdrawal of the notice or referral to the liaison procedure between funds, keeping a copy for the appeal file.

CSM bills call for a different check. Because the levy targets residents whose French professional income is below the threshold while capital income is substantial, the common errors fall into checkable groups: periods during which an S1 actually covered the person, years where professional income was wrongly understated or a spouse’s income wrongly aggregated, and pension or disability income that removes the person from the levy altogether under the second statutory condition. Recompute the year line by line against the notice, gather the S1 dates, the payslips and the pension statements, and challenge the precise line that is wrong rather than the levy in the abstract. Where none of these routes fits and the fund maintains the bill, the appeal ladder below takes over, but a file that already identifies the exact error at the first letter is resolved far faster than a file that merely protests.

Delays without a formal refusal deserve the same rigour. A file can sleep for six months while the applicant assumes silence means processing: it often means a missing document nobody requested in writing. After six to eight weeks without the attestation, send a recorded letter listing every document already filed with its date, asking what precisely is missing, and setting out that treatment costs are accumulating in the meantime. If no complete answer arrives, that letter becomes the starting point of the appeal time limits and the evidence that the fund, not the applicant, caused the gap. During the wait, keep every invoice and every prescription, pay what must be paid to stay treated, and note which sums were paid only because the card had not been issued: recoverable back payments depend on that paper trail.

B. How do you appeal a refusal, a double bill or months without a carte Vitale?

The appeal ladder has four rungs, and order matters. The first rung is the CRA, the commission de recours amiable, the fund’s own review board, which must be seized within the period stated on the decision letter, in practice two months from notification. The letter should be short and complete: reference the decision with its date, state precisely what is asked, annulment of the refusal, recording of the S1, opening of PUMA rights from the date of the complete file, or withdrawal of the contribution notice, then attach the numbered exhibits in the order cited. Ask expressly for a decision that states the reasons and the further appeal routes, because the next court will want to see that the prior review was attempted. Most well-documented files are resolved here, since a reviewer with the full bundle often corrects what a counter clerk with half the file got wrong.

The second rung is the court: the judicial court with its social protection division, the tribunal judiciaire, pôle social, hears disputes about affiliation, benefits and contributions. The claim must identify the exact periods and sums, attach the CRA decision or proof that the CRA was seized and did not answer in time, and frame the legal ground narrowly: competence of Britain under the S1 and the single-legislation rule for double bills, fulfilment of the stability and regularity conditions with dated proof for PUMA refusals, or error in the levy base for CSM notices. Bring originals plus copies, prepare a one-page chronology for the hearing, and ask for interest and backdating of rights where sums were paid during an unlawful gap. Judges in this division see coordination disputes weekly; a file that speaks their language, dates, documents, precise legal basis, is decided on its merits rather than adjourned for missing papers.

The third and fourth rungs are parallel rather than sequential. The fund’s médiateur, the independent reviewer inside the health insurance system, can unblock a file stuck between two offices or two countries without the formality of a court claim, and a concise referral with the chronology often produces movement within weeks. Separately, the Défenseur des droits, the national rights ombudsman, can be seized where a delay or refusal looks discriminatory or where a vulnerable person is left without cover; its intervention carries moral weight that funds take seriously. Neither route suspends the court time limits, so they should be launched alongside the CRA or the court claim, never instead of it. A word on urgent treatment: where care cannot wait, the immediate priority is treatment first and paperwork second, using the European card for temporary stays, private cover, or direct payment with full invoices kept for later recovery once rights are recognised with retroactive effect.

Continuity of rights during the dispute is protected by a provision many applicants overlook. The statute provides that persons who stop meeting one residence condition keep, within a one-year limit, an extension of their health cost cover: they bénéficient, dans la limite d’un an, d’une prolongation du droit à la prise en charge des frais de santé under the stated articles (Article L. 160-1 of the Social Security Code). In practice this means a change of status, a permit renewal gap, or the end of an S1 does not cut cover overnight; invoke the extension in writing the moment the situation changes, keep paying any contributions actually due, and the eventual decision can then backdate onto continuous rights instead of repairing a hole. Final housekeeping for the whole dispute: never surrender originals, answer every letter within its deadline even if the answer is that the requested document does not exist, and file the eventual judgment or settlement with the CPAM immediately so the card, the reimbursements and the contribution account are all aligned on the same dates.

Conclusion

British healthcare in France after Brexit is a system with two entrances and no side door. The S1 entrance serves State Pensioners, posted workers and frontier workers whose cover Britain certifies: obtain the form, register it at the CPAM, guard the attestation until the carte Vitale arrives, and refuse any parallel French health bill for the certified periods on the strength of the single-legislation rule. The PUMA entrance serves everyone else who lives here in a stable and lawful way: three months of provable presence, a lawful residence title, a complete file at the CPAM, then the same card and broadly the same basket of reimbursed care, with a top-up mutuelle or the means-tested public top-up on top. Early retirees with capital income add one more check, the annual CSM levy, before the budget is final. When the fund says no or bills twice, the method is the same in every case: identify the exact error, prove the competent state or the residence facts with dated papers, seize the CRA within the letter’s deadline, and then the court if needed, while treatment continues and every invoice is kept. Healthcare disputes are rarely about medicine and almost always about proof; the resident whose file proves dates, status and competence is the resident whose card arrives and whose bill falls.