Health of Cross-Border Workers: CNS, Form S1, Medical Care, and Sick Leave

Do you work in Luxembourg while living in France, Belgium, or Germany? As a cross-border worker, your health coverage depends both on your enrollment in the Luxembourg social security system and your registration with the health insurance fund in your country of residence.

This special status allows you to receive coverage for medical care in Luxembourg and in your country of residence, provided you complete certain administrative procedures. Form S1, Form BL1, reimbursement of medical expenses, sick leave, medical certificates, CNS check-ups, and co-insurance for family members: there are several key points you need to understand from the very start of your employment in Luxembourg.

This page explains how healthcare works for cross-border workers in Luxembourg, what steps to take, how to report sick leave, and what rights apply depending on your country of residence.

Summary

• Who is considered a cross-border worker in Luxembourg?
• How does health insurance enrollment work for cross-border workers in Luxembourg?
• Form S1, S072, or BL1: What are these documents used for?
• How do you cover your family members when you are a cross-border worker?
• Where can you receive medical care as a cross-border worker in Luxembourg?
• How do you get reimbursed for healthcare costs?
• Sick leave for cross-border workers: what steps should you follow?
• Authorized absences and CNS checks during sick leave for cross-border workers
• The most common health-related mistakes made by cross-border workers
• Health checklist for cross-border workers before starting work in Luxembourg
• Health in Luxembourg: What a cross-border worker needs to know
• FAQ: Frequently asked questions about the health of cross-border workers

Who is considered a cross-border worker in Luxembourg?

A cross-border worker is someone who works in Luxembourg but lives in another country, most often in France, Belgium, or Germany. They work in Luxembourg while regularly returning to their country of residence.

This situation entails specific rights regarding social security, healthcare, sick leave, and reimbursement. Cross-border workers pay contributions in Luxembourg, but they must also complete certain procedures in their country of residence to receive medical coverage there.

To better understand the applicable professional framework, see also our guide Working in Luxembourg: A Complete Guide for Expats and Cross-Border Workers.

How does health insurance enrollment work for cross-border workers?

When you start working in Luxembourg, your employer registers you with the Luxembourg Joint Social Security Center. You are then enrolled in the Luxembourg social security system and the National Health Fund.

This enrollment entitles you to Luxembourg health benefits. However, since you reside abroad, you must also be registered with the health insurance fund in your country of residence.

Why is dual health insurance registration necessary?

Dual enrollment allows cross-border workers to receive:

• healthcare in Luxembourg under Luxembourg rules;
• healthcare in their country of residence according to local rules;
• continuity of care between Luxembourg and the country of residence;
• clearer coverage for family members, subject to applicable conditions.

To better understand Luxembourg’s social security system, visit our page on Health Insurance Funds, Social Security, and Supplemental Health Insurance in Luxembourg.

Form S1, S072, or BL1: What are these documents for?

To establish your entitlement in your country of residence, the National Health Fund issues a document confirming your entitlement. This document varies depending on the country where you live.

Country of residence	Document typically used	Main procedure
France	S1 or S072 depending on the situation	Registration with the local CPAM office.
Belgium	BL1	Registration with the Belgian health insurance fund.
Germany	S1	Registration with the German health insurance fund.

What should you do if you do not receive your S1 or BL1 form?

In principle, the form is sent after you enroll in Luxembourg. If you haven’t received it within a reasonable time after enrolling, you can order it directly from the CNS.

Order an S1/S072 form from the CNS.

Order a BL1 form from the CNS.

How can you cover your family members if you are a cross-border worker?

Under certain conditions, the family members of a cross-border worker may be eligible for health coverage linked to the worker’s enrollment in Luxembourg.

Recognition as a dependent family member, however, depends on the rules of your country of residence. The local health insurance fund determines who is eligible and forwards the necessary information to the CNS.

If your spouse is employed in your country of residence, children or other family members can generally be covered under their local insurance rather than your Luxembourg coverage.

It is therefore important to verify your family situation with your local health insurance provider.

Where can you receive medical care if you are a cross-border worker in Luxembourg?

A cross-border worker can receive medical care in Luxembourg or in their country of residence. Reimbursement rules depend on the country where the care is received.

Care received in Luxembourg

Medical care received in Luxembourg is covered according to Luxembourgish rules. Cross-border workers can see a doctor, receive medical care, or purchase medications in Luxembourg under the same conditions as resident insured individuals, subject to applicable terms and conditions.

For medical procedures in Luxembourg, visit our page on medical consultations in Luxembourg.

Care received in your country of residence

Healthcare received in your country of residence is reimbursed according to local rules and rates. You must contact your local health insurance provider: CPAM in France, mutualité in Belgium, Krankenkasse in Germany.

Care received in another European country

If you need medical care in another country of the European Union, the European Economic Area, or Switzerland, the European Health Insurance Card can be used according to the rules applicable in the country concerned.

How do you get reimbursed for healthcare costs if you’re a cross-border worker?

Reimbursement depends on where the care was provided.

Location of care	Relevant agency	Reimbursement rules
Luxembourg	CNS	Reimbursement according to Luxembourg rules.
Country of residence	Local health insurance fund	Reimbursement according to the rules of the country of residence.
Other EU/EEA/Swiss countries	Depending on the situation	The European Health Insurance Card may be used.

To understand healthcare reimbursements, visit our page on Healthcare Reimbursement in Luxembourg.

Sick leave for cross-border workers: what steps should be taken?

In the event of illness, the cross-border worker must follow Luxembourg’s rules, even if they see a doctor in their country of residence.

What should you do on the first day of sick leave?

1. Notify your employer on the first day of absence.
2. See a doctor to obtain a medical certificate of incapacity for work if necessary.
3. Submit the medical certificate to the CNS and your employer within the required timeframe.
4. Include your Luxembourg social security number on the certificate if it is issued in your country of residence.
5. Keep a copy of all documents sent.

Learn more about sick leave and medical leave in Luxembourg.

Foreign medical certificate: what to check?

Depending on your country of residence, the certificate of incapacity for work may not have the same format as Luxembourg certificates. It is therefore recommended that you verify that the document contains the necessary information and request a duplicate from the doctor if a copy needs to be sent to your employer.

Your certificate must clearly identify:

• your first and last name;
• the start and end dates of the incapacity;
• your Luxembourg social security number, if possible;
• the information required by the CNS;
• the information to be provided to your employer.

Authorized absences and CNS checks during a cross-border sick leave

Cross-border workers are subject to the rules regarding leaving the country that apply during sick leave. Residing abroad does not exempt you from complying with the obligations set forth by the CNS.

Can you leave your home during the first five days of sick leave?

During the first five days of incapacity, outings are very limited. Travel necessary to attend a medical appointment, receive care, or complete health-related procedures may be authorized.

Starting on the 6th day: what outings are permitted?

Starting on the sixth day, outings may be authorized if the medical certificate permits it. They are then limited to certain time slots:

• from 10 a.m. to 12 p.m.;
• from 2:00 PM to 6:00 PM.

Checks at the cross-border worker’s residence

The CNS may conduct checks at the place of residence or stay indicated by the cross-border worker. Checks may take place from 8 a.m. to 9 p.m.

If the employee is absent at the time of the inspection, they must be able to justify their absence within the specified timeframe.

The most common health-related mistakes made by cross-border workers

Common mistake	Possible consequence
Failing to register your S1, S072, or BL1 form	Difficulties obtaining reimbursement in the country of residence.
Failing to notify the employer on the first day of illness	Risk of issues with the employer and loss of coverage.
Submitting the medical certificate after the deadline	Reminder, penalty, or coverage issues.
Failing to provide the Luxembourg social security number	Delay in processing by the CNS.
Leaving the house during sick leave without following the rules	Issues during an administrative audit.
Failure to verify family members’ coverage	Incomplete family registration or coverage errors.

To complete your health and employment procedures in Luxembourg

• Health insurance funds, social security, and supplemental health insurance
• Reimbursement of healthcare costs in Luxembourg
• Medical appointments in Luxembourg
• Sick leave in Luxembourg
• Labor law in Luxembourg
• Working hours and leave in Luxembourg
• Working in Luxembourg
• Taxation in Luxembourg

FAQ: Frequently Asked Questions About the Health of Cross-Border Workers

Healthcare coverage for cross-border workers in Luxembourg depends on effective coordination between the CNS and the health insurance fund in the country of residence. By taking prompt action and following the rules regarding sick leave, you ensure your health coverage and that of your family.