Declaration of incapacity for work

Important: Because of the COVID-19 pandemic, insured persons may send their certificates of incapacity for work exceptionally by e-mail to the following address: saisieCIT.cns@secu.lu

Furthermore, please indicate your 13-DIGIT NATIONAL NUMBER IN THE SUBJECT of your e-mail.

Declaration for residents

Insured persons are requested to use only the forms provided to them by their doctor, in accordance with the agreement reached between the CNS (Caisse nationale de santé) and doctors. This form consists of three sections and must include the following:

  • the 13-digit identification number of the person concerned (YYYYMMDDXXXXX, with YYYY=year of birth, MM=month of birth, DD=day of birth and XXXXX=5 personal digits)
  • the dates of commencement and termination of the period of incapacity for work
  • the diagnostic code
  • the date of the medical assessment
  • the stamp or signature of the prescribing physician

The insured sends the first section of the form (the original) to the CNS.

The second section should be sent to the employer, while the third section should be kept by the insured person for safekeeping.

Declaration for cross-border workers

As it is not always possible for cross-border workers to obtain certificates of incapacity for work in the form required in Luxembourg, here are some recommendations:

French cross-border workers: No major issue here, the French sick leave consists of both a section 1 (to be sent to the CNS) and a section 2 (to be sent to the employer).

German cross-border workers: As of 01.10.2021, the electronic certificate of incapacity for work (eAU) has been introduced in Germany. Doctors in Germany now transmit the incapacity for work of German insureds directly and electronically to the German health insurance funds. To declare their incapacity for work to the CNS, insureds in Luxembourg who consult a doctor in Germany must request a printout of the electronic certificate of incapacity for work. For more information on this, read our News of 12.11.2021.

Belgian cross-border workers: As the majority of Belgian certificates consist of one section only, the insured person should request a duplicate from their doctor to be submitted to the employer.

Important: 13-digit identification number

The 13-digit Luxembourg registration number (YYYYMMDDXXXXX, with YYYY=year of birth, MM=month of birth, DD=day of birth and XXXXX=5 personal digits) is required to register the medical certificate correctly.

If this number has not been mentioned by the foreign doctor on the medical certificate, the insured person may add it, but not in the sections of the form reserved for the doctor.

Any changes or additions to these sections are not permitted and may result in penalties and the invalidity of the certificate.

Deadlines for declaring incapacity for work

Incapacity to work for 1 or 2 days

The CNS does not require a medical certificate for incapacity for work lasting only one or two working days. There is also no need for the insured person to declare their incapacity by telephone to the CNS.

Incapacity to work for 3 days or more

The insured person must send the medical certificate to the CNS by the end of the third working day of incapacity for work at the latest (the date of the postmark serves as proof).

Example

An insured person working part-time, who is free on Mondays according to their work schedule and who falls ill on a Monday, must notify their employer of their illness on Tuesday (1st day of absence from work) and send a medical certificate to the CNS by Thursday (3rd day of absence).

Retroactive declaration

The medical certificate must be issued no later than the third day of the incapacity to work or its extension, i.e. with a retroactive effect of no more than two days.

Any medical certificate with a retroactive effect of more than two days can only be taken into account by the CNS from the date of its issue.

Example

The insured person is ill from Monday and visits a doctor on Wednesday, who issues a certificate of incapacity for work from Monday. In this case, the entire period of certified incapacity for work is taken into account by the CNS.

If the insured person sees a doctor on Thursday and the doctor issues a certificate from Monday, the retroactive effect goes beyond two days and the CNS only takes the certificate into account from the time it was issued, i.e. from Thursday.

Extension of incapacity for work

If incapacity for work extends beyond the initial period fixed, a form to this effect must be sent to the CNS before the end of the second working day, in other words the day which would have been the second working day following the employee's return to his/her job if incapacity had not been extended.

If the submission deadline falls on a Saturday, a Sunday or a public holiday, it is extended to the next working day.

Example

The insured person who is ill has a medical certificate until Tuesday. The sick leave is prolonged. The insured must send the new certificate to the CNS by Friday at the latest (the 2nd working day after the day initially scheduled for resumption of work, Wednesday).

If the insured has a certificate until Thursday and the sick leave must be prolonged, the extension must be sent by the following Monday at the latest (2nd day following the day of resumption is a Sunday, the deadline for sending is extended to the next working day, Monday).

Deadlines for information in the event of incapacity abroad 

Two different sets of circumstances need to be distinguished:

Stay in a member state of the European Union or in a state with which the Grand Duchy has reached an international agreement on social security matters

The insured person must send the certificate of incapacity for work to the CNS before the end of the third working day that the insured has been on sick leave. The date of the postmark is noted as proof of date of submission.

Stay in a a state not linked to the Grand Duchy by any international accord or protocol establishing the procedure to be followed in the case of incapacity for work or the extension of a period of incapacity for work

The insured person must send a medical certificate to the competent national health fund in Luxembourg within three days (the date of the postmark will be noted as proof of date of submission).

Penalties in case of a failure to make a declaration

If the insured fails to submit any medical certificate to the CNS, they will be reminded to do so in writing.

In the event of a repeated failure to submit documents, the CNS can impose a fine in accordance with article 447 of the Social Security Code (the fine cannot exceed 750 €).

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